Accident Report: Fatality Reference
PDF Version
FAI-F01E9A8-1
UNITED STATES
DEPARTMENT OF LABOR
MINE SAFETY AND HEALTH ADMINISTRATION
REPORT OF INVESTIGATION
Surface
(Industrial Sand)
Falling, Rolling, or Sliding Rock or Material of Any Kind Accident Fatality Report
March 3, 2026
J-Co Construction (C9995)
New Braunfels, Texas
Renteria Construction (C9701)
San Antonio, Texas
at
North American Silica Sand, LLC
North American Silica Sand, LLC
San Antonio, Bexar County, Texas
ID No. 41-05470
Accident Investigators
Belinda Youngblood
Mine Safety and Health Inspector
Karen Leliefeld
Mine Safety and Health Inspector
Originating Office
Mine Safety and Health Administration
Dallas District
1100 Commerce Street, Room 462
Dallas, Texas 75242
William O’Dell, District Manager
OVERVIEW
On March 3, 2026, at 1:08 p.m., Leandro Castro, a 63-year-old contract miner with about 16 days of mining experience, died after a concrete block retaining wall collapsed into the excavated footing below, crushing him.
The accident occurred because: 1) the mine operator and the contractor did not correct a hazardous ground condition before the contract miner commenced working in the area, 2) the mine operator did not place barricades or warning signs to prevent the operation of equipment above the excavation area, 3) the mine operator did not provide hazard awareness training to the contract miner, and 4) the contractor did not provide new miner training to the contract miner.
GENERAL INFORMATION
North American Silica Sand, LLC owns and operates the North American Silica Sand, LLC mine, an industrial sand mine located in Bexar County, Texas. North American Silica Sand, LLC employs six miners and operates one 12-hour production shift 4 days per week. The mine uses an open pit mining method. Excavators remove overburden and haul trucks transport material to the wash plant. The wash plant separates sand and rock using belt conveyors. Material is stockpiled and then sold to the public and the construction industry.
North American Silica Sand, LLC contracted A. G. Irvin Steel Erectors to build a dry sand storage building that was under construction at the time of the accident. North American Silica Sand, LLC contracted Axis Engineering to design a new retaining wall. North American Silica Sand, LLC contracted J-Co Construction to replace the existing concrete block retaining wall. J-Co Construction subcontracted Renteria Construction to construct a concrete footing for the new wall. Castro was employed by Renteria Construction.
The principal management officials at the North American Silica Sand, LLC mine at the time of the accident were:
Geoff Hicks Owner/President
Ignacio Martinez Owner
Sydney Hokamp Plant Manager
The principal management official at J-Co Construction at the time of the accident was:
Jason Miller Owner
The principal management official at Renteria Construction at the time of the accident was:
Francisco Renteria Owner
The principal management official at Axis Engineering at the time of the accident was:
Roger Martinez Physical Engineer
The Mine Safety and Health Administration (MSHA) completed the last regular safety and health inspection at this mine on July 14, 2025. The 2025 non-fatal days lost incident rate for the North American Silica Sand, LLC mine was zero, compared to the national average of 1.19 for mines of this type.
DESCRIPTION OF THE ACCIDENT
On March 3, 2026, at 7:13 a.m., Castro began his shift by signing in at the mine office. At 7:30 a.m., Castro began using a hand shovel to remove and level material on the inside of the footing excavation. Jose Renteria, contract miner for Renteria Construction, removed material from inside of the footing excavation using a Bobcat mini excavator. The Bobcat mini excavator was located outside the footing excavation.
Castro continued his work inside the footing until around 11:30 a.m. From 11:30 a.m. to 12:50 p.m., Castro assisted Jason Miller, owner of J-Co Construction, and Francisco Renteria, owner of Renteria Construction, with taking measurements and surveying elevations to troubleshoot an issue with the footing’s elevation. At 12:51 p.m., Castro continued his work inside the footing excavation using a hand shovel to level material to correct the elevation issue. J. Renteria relocated the Bobcat mini excavator inside of the footing excavation, closer to the retaining wall, at about 1:00 p.m. to remove material.
At 1:08 p.m., Castro was inside the footing excavation area preparing the footing. An 80-foot-long section of the concrete block wall collapsed into the footing excavation area below, crushing Castro beneath the blocks. J. Renteria immediately asked Barbara Nunez, administrative assistant for North American Silica Sand LLC, to call 911. Nunez called 911 at 1:09 p.m.
From 1:11 p.m. to 1:25 p.m., J. Renteria and David Cintron, contract miner for Renteria Construction, assisted Edgar Trevino, foreman for A.G. Irvin Steel Erectors, and Sydney Hokamp, foreman for North American Silica Sand LLC, in recovery efforts. EMS arrived on-site, and Dr. Bryan Everett pronounced Castro deceased at 1:33 p.m.
INVESTIGATION OF THE ACCIDENT
On March 3, 2026, at 1:14 p.m., Nunez called the Department of Labor National Contact Center (DOLNCC) to report the accident. The DOLNCC contacted Neal Davis, supervisory mine safety and health inspector. Davis contacted Brett Barrick and Ronnie Free, assistant district managers. Barrick contacted Ty Fisher, supervisory mine safety and health inspector, to assist. Free contacted Thomas Kelly, supervisory mine safety and health inspector, who assigned Belinda Youngblood, mine safety and health inspector, as the lead investigator. Barrick also sent Karen Leliefeld, mine safety and health inspector, to assist with the investigation.
At 1:47 p.m., Fisher issued a verbal 103(j) order under the authority of the Federal Mine Safety and Health Act of 1977, to ensure the safety of all persons at the mine and require the operator to obtain the approval of an authorized representative for any plan to recover any person in the mine. Nunez notified Fisher at 1:53 p.m. of Castro’s passing.
At 3:20 p.m., Leliefeld arrived at the mine, secured the scene, and gathered preliminary information. Fisher arrived at the mine at 3:31 p.m., modified the 103(j) order to a 103(k) order, under the provisions of Section 103(k) of the Mine Act, to ensure the safety of the miners and the preservation of evidence. At 5:45 p.m., Youngblood arrived at the mine and began her investigation.
MSHA’s accident investigation team conducted an examination of the accident scene; interviewed miners, mine operator management, contractors, contractor management, and other relevant personnel; reviewed surveillance video; and reviewed the conditions and work practices relevant to the accident. For reference, a list of people who participated in the investigation can be found in Appendix A.
DISCUSSION
Location of the Accident
The accident occurred within the footing excavation for a new retaining wall that was being constructed on the western side of a dry sand storage building area that was under construction. The new retaining wall was being constructed in front of an existing retaining wall.
Weather
The weather at the time of the accident was clear, 89 degrees Fahrenheit, with south-southeast winds at 12 miles per hour. Investigators determined that the weather did not contribute to the accident.
Ground Conditions
The existing retaining wall was built using concrete blocks, each measuring 4 feet in length, 2 feet in width, and 2 feet in depth, and weighing about 800 pounds each. The blocks were stacked four blocks high, in total measuring nearly 285 feet in length, and 8 feet in height. The concrete blocks had not been secured in place. They were simply resting on top of one another. The area above the existing retaining wall was being used as an access point for the JLG 460 Man Lift to travel and continue working on the sand storage building while work was being performed on the retaining wall. The footing excavation for the new retaining wall that was being constructed in front of the existing retaining wall measured nearly 220 feet in length, 3 feet in depth, and 8 feet in width.
The mine operator observed that the existing retaining wall was not permanently fixed; was unstable; was leaning out, away from the building; and needed to be reinforced. The mine operator contacted Axis Engineering in November 2025 to evaluate the construction of a new building. Mine management, J-Co construction, and Axis Engineering met on February 9, 2026. Prior to this meeting, the existing retaining wall was two to three layers high. During this meeting, Axis Engineering noticed the existing retaining wall had grown to four layers high. The existing retaining wall was discussed, specifically the portion of the wall that showed signs of leaning. Axis recommended the top two layers of blocks be removed along the stacked block wall length.
On March 3, 2026, when Axis Engineering arrived on-site to assist with the footing elevation issue, they noticed that the top two layers of blocks had not been removed. Axis Engineering recommended that the layers be removed before work continued. Instead of correcting hazardous ground conditions or preventing contract miners from being exposed to the hazardous ground conditions, North American Silica Sand, LLC’s managers Geoff Hicks and Sydney Hokamp, as well as Jason Miller of J-Co construction, allowed contract miners to continue to work in the area, knowing the retaining wall was unstable.
These factors created hazardous ground conditions. Investigators determined that the mine operator and J-Co Construction did not correct known hazardous ground conditions, which contributed to the accident.
Examinations
During witness interviews, investigators learned that on the day of the accident, neither mine management (Hicks and Hokamp) nor J-Co construction conducted a workplace examination. Investigators determined that the lack of examination did not contribute to the accident because the hazardous condition was previously identified. The mine operator was aware of the hazard caused by the existing retaining wall based on previous visual observations of the area. Individuals in the area at the time of the accident were there to correct the conditions by constructing a new concrete retaining wall.
Training and Experience
Castro had about 16 days of mining experience, all at North American Silica Sand. Castro had 40 years of experience in concrete construction work. Investigators determined a lack of new miner and site-specific hazard awareness training contributed to the accident.
ROOT CAUSE ANALYSIS
The accident investigation team conducted an analysis to identify the underlying causes of the accident. The team identified the following root causes, and the mine operator and the contractor implemented the corresponding corrective actions to prevent a recurrence.
1. Root Cause: The mine operator and contractor did not correct a hazardous ground condition before the contract miner commenced working in the area.
Corrective Action: The ground condition was corrected by removing the stone block retaining wall and grading the slope to remove any other hazardous ground condition.
2. Root Cause: The mine operator did not install barricades and warning signs to prevent mobile equipment from operating above where the contract miners were working.
Corrective Action: The mine operator has added barricades to stop vehicular traffic near the side of the building above the sloped area.
3. Root Cause: The mine operator did not provide hazard awareness training.
Corrective Action: The mine operator has developed, implemented, and trained employees on a standard operating procedure for validating training for all contractors.
4. Root Cause: The contractor did not provide new miner training.
Corrective Action: The contractor will not be returning to the mine site or any other mine site until required training has been submitted to MSHA for review.
CONCLUSION
On March 3, 2026, at 1:08 p.m., Leandro Castro, a 63-year-old contract miner with about 16 days of mining experience, died after a concrete block retaining wall collapsed onto the excavated footing below, crushing him.
The accident occurred because: 1) the mine operator and the contractor did not correct a hazardous ground condition before the contract miner commenced working in the area, 2) the mine operator did not place barricades or warning signs to prevent the operation of equipment above the excavation area, 3) the mine operator did not provide hazard awareness training to the contract miner, and 4) the contractor did not provide new miner training to the contract miner.
Approved By:
_____________________
William O’Dell Date
District Manager
ENFORCEMENT ACTIONS
1. A 103(k) order was issued to North American Silica Sand, LLC.
A fatal accident occurred on March 3, 2026, at 1:08 p.m. This order is being issued under the authority of the Federal Mine Safety and Health Act of 1977, under Section 103(k) to insure the safety of all persons at the mine and requires the operator to obtain the approval of an authorized representative of MSHA of any plan to recover any person in the mine or to recover the mine or affected area. This order prohibits any activity in the affected area. The operator is reminded of the obligation to preserve all evidence that would aid in investigating the cause or causes of the accident in accordance with 30 CFR 50.12
2. A 104(d)(1) citation issued to North American Silica Sands, LLC for a violation of 30 CFR 56.3200.
On March 3, 2026, a contract miner was fatally injured while preparing a footing inside an excavated area. The mine operator did not take down or support hazardous ground conditions before work or travel was permitted in the affected area. The mine operator engaged in aggravated conduct constituting more than ordinary negligence in that they were aware the wall was not stable and allowed contract miners to work in the affected area. This violation is an unwarrantable failure to comply with a mandatory standard.
3. A 104(d)(1) citation issued to J-Co Construction for a violation of 30 CFR 56.3200.
On March 3, 2026, a contract miner was fatally injured while preparing a footing inside an excavated area. The contractor did not take down or support hazardous ground conditions before work or travel was permitted in the affected area. The contractor engaged in aggravated conduct constituting more than ordinary negligence in that they were aware the wall was not stable and allowed contract miners to work in the affected area. This violation is an unwarrantable failure to comply with a mandatory standard.
4. A 104(d)(1) order issued to North American Silica Sands, LLC for a violation of 56.20011.
On March 3, 2026, a contract miner was fatally injured when an unstable retaining wall collapsed while he was preparing the footing inside an excavated area. The mine operator did not barricade or post warning signs prohibiting mobile equipment operation where it adversely affected the stability of the retaining wall. The mine operator engaged in aggravated conduct constituting more than ordinary negligence in that he was aware the retaining wall was not stable and allowed contract miners to operate mobile equipment in this manner. This violation is an unwarrantable failure to comply with a mandatory standard.
5. A 104(d)(1) order issued to North American Silica Sands, LLC for a violation of 30 CFR 46.11.
On March 3, 2026, a contract miner was fatally injured while preparing a footing inside an excavated area. The mine operator did not provide adequate site-specific hazard awareness training to the contract miner before they began preparing the footing adjacent to the concrete block retaining wall. The mine operator engaged in aggravated conduct constituting more than ordinary negligence by not providing adequate site-specific hazard awareness training addressing mine hazards at the location the contract miner was hired to work. This violation is an unwarrantable failure to comply with a mandatory standard.
6. A 104(d)(1) order issued to J-Co Construction for a violation of 30 CFR 46.5.
The contractor did not provide the required new miner training to a contract miner who was fatally injured on March 3, 2026. The contractor did not ensure the miner received a minimum of 4 hours of new miner training, including training on the safety aspects of primary work tasks before beginning work. The contractor engaged in aggravated conduct constituting more than ordinary negligence by not providing new miner training. This violation is an unwarrantable failure to comply with a mandatory standard.
APPENDIX A – Persons Participating in the Investigation
North American Silica Sand, LLC
Geoff Hicks Owner/President
Ignacio Martinez Owner
Sydney Hokamp Plant Manager
Barbara Nunez Administrative Assistant
J-Co Construction
Jason Miller Owner
Renteria Construction
Francisco Renteria Owner
David Cintron Contract Miner
Jose Renteria Contract Miner
Axis Engineering
Ethan Green Engineer
Roger Martinez Engineer
Mine Safety and Health Administration
Ty Fisher Supervisory Mine Safety and Health Inspector
Karen Leliefeld Mine Safety and Health Inspector
Belinda Youngblood Mine Safety and Health Inspector