A Mystic woman injured in last week's train crash in Bridgeport filed suit against Metro-North Friday.

The federal lawsuit filed by Elizabeth and Peter Sorensen states that the railroad company's negligence caused the crash. The lawsuit, filed by Stratton and Faxon of New Haven, does not provide specific allegations.

On May 17, the eastbound 4:41 p.m. train out of Grand Central Terminal in New York derailed just east of the Fairfield Metro station. The westbound 5:35 p.m. train from New Haven then struck the side of the eastbound train.

Elizabeth Sorensen, 65, was a passenger on the train returning to Connecticut from Grand Central Station.

There were 70 people injured in the crash. Sorensen is one of three still in a hospital.

The lawsuit states she suffered severe fractures to her legs, arm, and pelvis, and has already undergone multiple surgeries. She also sustained brain trauma when she was thrown around the interior of the train at the time of its derailment. She is expected to remain hospitalized for several months, her lawyer said.

"We've filed the case in federal court to permit access to witnesses, information and obtain subpoena power," attorney Joel T. Faxon said. "Public transportation has to provide the highest level of safety to passengers. Given what happened here that level of safety was clearly not delivered."

The crash is being investigated by the National Transportation Safety Board. On Friday, the NTSB said it is focusing on maintenance work performed on the tracks a few weeks before the accident.

NTSB spokesman Nicholas Worrell said that records of maintenance work done in the area of the derailment revealed that a joint bar, used to join two sections of rail together, was cracked and was repaired at that time by Metro-North personnel.

Worrell said sections of rail in the area of the derailment have been removed and shipped to the NTSB laboratory in Washington for further examination. In addition, Metro-North is conducting an inspection and inventory of all the joint bars on its main line tracks.

"Several areas of negligence have already been identified, but to date victims have not been given any access to the scene nor any of the evidence gathered there," Faxon said. "The NTSB has stated that cracks developed in a joint bar connecting tracks shortly before this calamity. We are going to scrutinize the track repair using our own metallurgists."