Two companies and two executives have been indicted on federal charges in the deaths of five workers in a 2007 fire inside a tunnel at a Colorado hydroelectric plant.

Xcel Energy, RPI Coating Inc. and two RPI executives face criminal charges in the deaths in a federal indictment that alleges they knew about the danger and did nothing about it. The 17-page indictment, made public Friday, accuses RPI of trying to cover up shortfalls by altering, destroying, or concealing the cameras, journals and cell phones of two of the dead workers.

Four people survived the fire at the Xcel Cabin Creek hydroelectric plant in Georgetown, Colo., about 35 miles west of Denver. All five of the workers killed worked for Santa Fe Springs, Calif.-based RPI.

In a statement, Xcel said it was a tragic accident.

“We reject any attempt to characterize the Cabin Creek events in any other way,” Xcel said.

Calls to RPI were referred to Denver attorney Larry Pozner, who echoed Xcel’s statement and said the five men weren’t simply employees, but “friends” who were highly trained industrial painters.