Bridgeport — The commuter train derailment and collision that left dozens injured outside New York City was not the result of foul play, officials said Saturday, but a fractured section of rail is being studied to determine whether it is connected to the accident.

National Transportation Safety Board member Earl Weener said Saturday the broken rail is of substantial interest to investigators and a portion of the track will be sent to a lab for analysis.

Weener said it's not clear whether the accident caused the fracture or whether the rail was broken before the crash. He said he won't speculate on the cause of the derailment and emphasized the investigation was in its early stages.

Seventy-two people were sent to the hospital Friday evening after a Metro-North train heading east from New York City derailed and was hit by a train heading west from New Haven. Most of the victims have been discharged.

Officials earlier described devastating damage and said it was fortunate no one was killed.

"All of the injured people described the really harrowing experience of having the train jolt to a stop, the dust, darkness, other kinds of factors that made it particularly frightening," said U.S. Sen. Richard Blumenthal, who visited several patients in the hospital.

Blumenthal, D-Conn., said a Metro-North conductor helped passengers despite her own injuries.

"Her story is really one of great strength and courage helping other passengers off the train in spite of her own very severe pain," Blumenthal said. "She eventually had to be helped off herself."

The crash damaged the tracks and threatened to snarl travel in the Northeast Corridor. The crash also caused Amtrak to suspend service indefinitely between New York and Boston.

"The damage is absolutely staggering," Blumenthal said, describing the shattered interiors of the cars and tons of metal tossed around. "I feel that we are fortunate that even more injuries were not the result of this very tragic and unfortunate accident."

U.S. Sen. Chris Murphy, D-Conn., said it was "frankly amazing" people weren't killed.

Both said new Metro-North Railroad cars built with higher standards may have saved lives.

Metro-North said train service will remain suspended between South Norwalk and New Haven until further notice. Railroad officials said rebuilding the two tracks and restoring train service "will take well into next week."

"We want our customers to know that while you travel on Metro-North, you can remain confident that your safety, and the safety of our employees, is always the first priority in everything we do," Howard Permut, president of MTA Metro-North Railroad, said.

NTSB investigators arrived Saturday and are expected to be on site for seven to 10 days. They will look at the brakes and performance of the trains, the condition of the tracks, crew performance and train signal information, among other things.

When the NTSB has concluded the on-site phase of its investigation, Metro-North will begin to remove the damaged rail cars and remaining debris. The process requires specialized, heavy equipment that will be in place by today, officials said. Only after the damaged train cars have been removed can Metro-North begin the work of rebuilding the damaged tracks and overhead wires.

"It is a significant undertaking that could take days to complete," MTA said in a statement.

The NTSB has allowed Metro-North to begin removing some of the track and wire from the scene.

Gov. Dannel P. Malloy said commuters should make plans for alternative travel through the area and urged them to consult the state Department of Transportation website for information.

Weener said data recorders on board are expected to provide the speed of the trains at the time of the crash and other information.

"Our mission is to understand not just what happened but why it happened and determine ways of preventing it from happening again," Weener said.

A chaotic scene

About 700 people were on board the Metro-North trains when one heading east from New York City's Grand Central Terminal to New Haven derailed about 6:10 p.m. just outside Bridgeport, transit and Bridgeport officials said. Passengers described a chaotic, terrifying scene of crunching metal and flying bodies.

A spokeswoman for St. Vincent Medical Center said late Saturday that 46 people from the crash were treated there, with six of them admitted. All were in stable condition, she said.

A Bridgeport Hospital spokesman said 26 people from the crash were treated there, with three of them admitted. One was in critical condition and two were in stable condition, he said. The other 23 were released.

Bridgeport Mayor Bill Finch said the disruption caused by the crash could cost the region's economy millions of dollars.

Passenger Frank Bilotti said he was returning from a business trip in Boston on the westbound train when it crashed.

"Everybody was pretty much tossed around," said Bilotti, 53, of Westport, who said he was uninjured except for a sore neck.

Firefighters used ladders to help people evacuate after the derailed cars dug into the banks of the tracks, Bilotti said.

"There were people on stretchers," he said. "There were people lying on the ground."

Blumenthal credited first responders, saying their "quick reactions and heroic efforts undoubtedly saved lives."

The MTA operates the Metro-North Railroad, the second-largest commuter railroad in the nation. The Metro-North main lines — the Hudson, Harlem, and New Haven — run northward from New York City's Grand Central Terminal into suburban New York and Connecticut.

The last significant train collision involving Metro-North occurred in 1988 when a train engineer was killed in Mount Vernon, N.Y., when one train empty of passengers rear-ended another, railroad officials said.

Weekend plans disrupted

In New London, three cadets from the Coast Guard Academy were looking forward to an overnight in New York City, where they planned to shed their uniforms and relax away from campus.

But Stephen Board of Moundsville, W.V., Nicholas Egersdorf of Rochester, Minn., and Kyneesha Womack of Mobile, Ala., were unaware early Saturday afternoon that a train had derailed and service to New York was canceled.

The three, who are finishing their first year at the academy, were sitting forlornly in Union Station at about 12:30 p.m., wondering what to do next.

"We just wanted to see the city and get away for a while,'' Board said. The three, according to Egersdorf, had to work hard to get the time off.

"Maybe we'll head to Boston,'' Board said.

A couple from New Zealand, who was staying on Fishers Island and needed to get to Providence for a conference at the Renaissance Hotel, was facing a four-hour delay for their northbound train Saturday afternoon.

They sat in Union Station eating sandwiches off their luggage.

"It's a minor blip for us,'' said Charlotte Gendall, who was traveling with her husband Warwick Gendall, a retired judge in New Zealand who is scheduled to give a presentation next week at the Association of Paroling Authorities International. He is president of the New Zealand Parole Board.

"We have to be back in New York on Wednesday,'' she said. "So hopefully the trains will be up and running by then."

Eventually, they got a refund on their Amtrak tickets and opted for a $125 taxi ride for the 50-mile trip to Providence.

Passengers who have paid but have chosen not to travel due to the service disruption may receive a refund or a voucher for future travel. Some reservations booked online can be modified or canceled on Amtrak.com or by using the free Amtrak mobile app. For more information, call (800) USA-RAIL or visit Amtrak.com/alerts or Amtrak.com.

Day Staff Writer Kathleen Edgecomb contributed to this report.