The sons of a woman who died after smoke filled a Washington subway train are suing the Metro transit agency for $50 million.

Attorney Patrick Regan filed the lawsuit Friday on behalf of Marcus and Anthony Glover, the adult sons of Carol Glover.

The lawsuit accuses Metro of negligence that led directly to the 61-year-old Glover's death. It says she was trapped on the smoke-filled train near the L'Enfant Plaza station for 45 minutes before rescuers arrived. At that point, the lawsuit says she had no pulse.

The lawsuit also says ventilation fans in the subway tunnel didn't work properly.

More than 80 other people were sickened by the smoke during the Jan. 12 accident, which was caused by an electrical malfunction. What led to the malfunction is under investigation.