The first lawsuits resulting from the deadly Amtrak commuter train derailment in Philadelphia last week have been filed. The lawsuits were filed just as the U.S. rail service resumed its operations on the heavily travelled Northeast Corridor.

Personal-injury lawyers Robert Mongeluzzi and Tom Kline have filed a federal complaint on behalf of four passengers who were injured during the derailment. Mongeluzzi and Kline have garnered a reputation for representing victims in some of Philadelphia's worst disasters, according to Philly.com.

The first four among the passengers to officially seek legal intervention in the Amtrak incident were 64-year old Felicidad "Feli" Redondo Iban, a retiree from Spain, 43-year old Daniel Armyn, a Brooklyn, N.Y.- based advertising executive, 39-year old Amy Miller of Princeton, N.J., and 55-year old Maria Jesus "Susu" Redondo Iban, Felicidad's cousin.

The lawsuit is the first case brought by a non-employee of the U.S. passenger rail service in connection with the accident, according to Reuters. An Amtrak worker who was in the train when the accident happened filed a lawsuit last week, citing a brain injury that he claims was a result of the derailment.

Mongeluzzi and Kline have also laid blame on the 32-year old engineer Brandon Bostian, who was controlling the train's speed when it went off the tracks, according to Philly.com.

"Speed kills," Mongeluzzi said. "That engineer had a sacred and solemn responsibility for the safety of his passengers. Nothing else matters ... I can find no excuse for speeding 106 mph into a 50 mph curve."

The engineer's claim that he has no memory of what happened in the crash was also "suspicious," according to the lawyers.

"It always raises red flags when someone who's been involved in an accident going too fast has a sudden claim of no memory," Mongeluzzi said.

"Any claim that he was temporarily incapacitated is inconsistent with everything that's been said so far. Afterward, he was outside (the mangled cars) speaking to people, and he appeared totally lucid," he added.

An Amtrak representative could not be immediately reached for comment, according to Reuters.