FAIRFIELD, Conn. – Officials described a devastating scene of shattered cars and other damage where two trains packed with rush-hour commuters collided in Connecticut, saying Saturday it’s fortunate that no one was killed and that there weren’t even more injuries.

Seventy-two people were sent to the hospital Friday evening after the crash, which damaged the tracks and threatened to snarl travel in the Northeast Corridor.

“The damage is absolutely staggering,” said U.S. Sen. Richard Blumenthal, D-Conn., describing the shattered interior of 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., echoed that, saying it was “frankly amazing” people weren’t killed on scene.

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

Officials couldn’t say when Metro-North service would be restored. The crash also caused Amtrak to suspend service between New York and Boston.

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.

“I think this is going to be with us for a number of days,” the governor said.

National Transportation Safety Board 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.

NTSB board member Earl Weener said he would not speculate on a cause for the collision. He 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.

Asked whether there were any signs of foul play and if investigators could rule out any cause, Weener said: “It’s too early to rule out anything. We just got on scene. That, of course, will be something we look at immediately.”

But Blumenthal referred to the crash as an accident and Malloy said Friday there was no reason to believe it was anything other than that.

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 at 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.

“All I know was I was in the air, hitting seats, bouncing around, flying down the aisle and finally I came to a stop on one seat,” said Lola Oliver, 49, of Bridgeport. “It happened so fast I had no idea what was going on. All I know is we crashed.”

The train was hit by a train heading west from New Haven to Grand Central on an adjacent track, Metropolitan Transportation Authority spokesman Aaron Donovan said. Some cars on the second train derailed as a result of the collision.