 A Dallas fire rescue engine crashed off an expressway bridge Sunday and landed on a railway truck below, injuring four firefighters. It happened just after 6 a.m. on the I-345 expressway, according to Dallas Fire and Rescue. It wasn't immediately known what caused the accident or if other vehicles were involved. All four firefighters were taken to Baylor University Medical Center, where they were listed in stable condition. Portions of the expressway and the Dallas area rapid transit rail system were shut down.