Rotary Bucket Excavator Operator

EE was operating an excavator in Pit 2 at SPS Atascosa. Pit 2 is located between two tailings ponds. 9:18 AM one of the tailings ponds breached causing tailings mixture to flow into the work site. Tailings mixture tipped over the excavator EE was operating cab side down. The front window broke, tailings mixture engulfed the cab & 75% of the vehicle. Employee could not escape.

On May 1, 2025, at 9:18 a.m., Alan Josue Castillo Herrarte, a 25-year-old contract heavy equipment operator with two years and seven months of mining experience, died after a section of the waste tailings pond retaining dam ruptured, allowing material to escape the impoundment. The material pushed the excavator he was operating off a bench, causing it to overturn and become engulfed in the material. The accident occurred because the mine operator and contractor did not: 1) substantially construct and inspect the retaining dam at regular intervals, 2) conduct a workplace examination in Pit 2C before miners began work. Additionally, the mine operator did not use mining methods to maintain wall, bank, and slope stability.

1. The mine operator and contractor did not substantially construct and inspect the retaining dam at regular intervals.

2. The mine operator and contractor did not conduct a workplace examination in Pit 2C before miners began work.

3. The mine operator did not use mining methods to maintain wall, bank, and slope stability.

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Findings from MSHA's final investigation report, which supersedes the preliminary narrative above.

Activity at time of incident

Power Shovel, Dragline

Subunit / location

STRIP, QUARY, OPEN PIT

Accident type

Struck by rolling or sliding object

Source of injury

BROKEN ROCK,COAL,ORE,WSTE

Nature of injury

UNCLASSIFIED,NOT DETERMED

Body part affected

MULTIPLE PARTS (MORE THAN ONE MAJOR)

Total mining experience

2 years

Experience at this mine

2 years

Experience in this job

2 years

Degree of injury

FATALITY