RIVERTON (WNE) — Two Fremont County local men died in an explosion Wednesday afternoon at the railcar repair yard in Shoshoni.

The victims – an 18-year-old from Shoshoni and a 28-year-old from Riverton, both employees at Wasatch Rail Repair – were inside a railcar when the blast occurred, Shoshoni Police Department chief Chris Konija said Thursday.

“(They were) doing maintenance and using equipment to scrape away paint or measure the integrity of the welds in the metal walls,” he said.

Officials presume an ignition source — a spark of some kind — met with flammable gases in the confined space to cause the explosion, which appears to have been accidental, according to a preliminary investigation.

The blast, which could be heard from as far as 10 miles away, was reported at about 3:25 p.m. Wednesday.

Konija said SPD officers arrived within two minutes of the call. By that point, the two men in the tanker were unresponsive.

Initial communications on emergency radio reported that the men could be heard trying to escape, but they fell silent shortly after that.

He noted that the blast did not lead to a fire outbreak, as the explosion vented through the manhole at the top of the railcar, creating some damage inside the shop building before extinguishing itself.

One of the first Fremont County firefighters to respond to the scene attempted to enter the tanker to rescue the men inside, officials said Thursday.

Because of the high levels of hydrogen sulfide and carbon monoxide present in the railcar, the firefighter had to self-evacuate soon after entering the container.