The criminal trial over the deaths of five workers at a Colorado hydroelectric plant is continuing in Denver.
Proceedings resumed in federal court on Monday, with lawyers for Minneapolis-based Xcel Energy Inc. and a subsidiary presenting their case.
The companies face five counts of violating federal safety regulations. Five workers from California died as a result of smoke inhalation when a fire trapped them inside a tunnel in October 2007 near Georgetown, about 40 miles west of Denver.
Prosecutors rested their case last week.
They argue Xcel knew of workplace safety violations. The defense says a contractor violated the regulations and the deaths were an accident.
If convicted, each company would have to pay fines up to $2.5 million and be subject to strict post-conviction supervision.