FOUNTAIN, Colo. (CBS4) – Two workers were killed on Thursday morning in Fountain after the drilling truck they were in caught fire.

CBS4 partner KKTV reports there was an explosion at approximately 9:30 a.m. and the truck burst into flames by Interstate 25 near the Ray Nixon edit.

The fire sent up a large plume of black smoke that could be seen for miles.

The workers were drilling for samples when witnesses said the truck went up in a fireball.

Colorado Springs Chief of Staff Jamie R. Fabos released this statement: “On behalf of the City of Colorado Springs, I’d like to extend my deepest sympathies to the families and friends of the two subcontractors who perished in today’s accident near Ray Nixon Road. We are especially saddened to learn that these were such young men, taken much too soon. We understand that a small grass fire resulted from the accident and we thank CSFD, CSPD and the Fountain Police and Fire Departments for their quick response in mitigating additional harm.”

The cause of the fire hasn’t been determined so far. The names of the workers haven’t been released.