LOS ANGELES — The conductor aboard the commuter train that collided with a freight train in September told investigators the warning light along the track was green before the crash that killed 25 people, his attorney said Thursday.

The claim contradicts findings from federal investigators that the Metrolink train ran a red light and caused the wreck _ the nation's deadliest rail disaster in 15 years. The National Transportation Safety Board has said three tests showed the signal system was working.

Conductor Robert Heldenbrand told investigators he saw the green light as the train was leaving a station about a mile from where it crashed into the Union Pacific freight, said John Gilbert, Heldenbrand's attorney.

"He checked the platform prior to the (train) doors closing to make sure there were no more passengers," he told the Los Angeles Times. "That's when he observed the green light."

Gilbert said he was with Heldenbrand when he was interviewed by investigators.

Metrolink spokesman Francisco Oaxaca would not comment on the details of the investigation and could not say if the signal could have turned red after the train left the station.

However, he said that because trains are heavy and difficult to stop quickly, "the system tells you what to do, two or three signals ahead."

Investigators said engineer Robert Sanchez, who was killed in the collision, was supposed to stop the train at the red signal just before a switch intended to guide the freight train onto a side rail. Instead, Sanchez passed the switch at 42 mph before colliding head-on with the freight on a curve about a quarter-mile farther, according to federal investigators.

Cell phone records show that Sanchez was text messaging 22 seconds before the crash. Toxicology reports came back clean.