BRIDGEPORT - Saturday marks one year since a Metro-North train derailed and crashed on the Bridgeport-Fairfield Line, injuring dozens.

For first responders, the day was a test of their skills. Fairfield Assistant Fire Chief Scott Bisson was one of the first people on the scene, and says it was probably one of the most overwhelming incidents he's ever responded to in 23 years.

The train was carrying 500 passengers at the time of the crash. 70 people were hurt.

The head of the Emergency Department at Bridgeport Hospital says they saw about 50 patients, four of which were critical.

He says it was a chaotic situation because all those people came in at once, but luckily the department had held a mass casualty training drill earlier that week. He says the same staff that participated in the drill was on duty at the time of the derailment, so they were able to handle everything very smoothly.

Federal safety officials later determined that a portion of damaged track caused the train to derail.

Fairfield fire officials say that they have planned training for their staff to focus on how to respond to such situations and get more familiar with train operations.