An Amtrak derailment in Penn Station on Friday caused a cascade of delays and cancellations for three railroads.

New Jersey Transit said service resumed at 4 p.m, but with limited outbound service from Penn Station.

Rail service had been suspended since a minor train derailment in the morning.

Amtrak said one of its Acela Express trains, Acela Train 2151, was moving slowly out of the station when it derailed and struck a New Jersey Transit train.

It happened around 9 a.m. Friday. At the time, there were 248 people aboard the Washington-bound Amtrak train.

Amtrak trains were still running with delays as of Friday night.

Two people suffered minor injuries, but neither required treatment at the hospital.

"We were leaving Penn, heading south, there was a bang, there was a thud, there was a bit of rattling," one witness recalled.

The accident made a huge mess of rail travel into and out of Penn Station, and along the busy northeast corridor.

Lines were long and tempers were short all day at the rail terminal.

"I want to get home. I got things to do, places to go, and it's frustrating not knowing what's going to happen," one traveler said. "If it's going to be canceled, delayed, or who knows how long I'll be here."

"Nobody has an answer, they can't tell us where to go, they don't know when the trains are going to come back up," another commuter said.

The Acela train was moving at a slow speed when some of the front cars skipped the tracks and clipped the NJ Transit train on a parallel track.

"We're all very blessed that we weren't going fast, that nobody was hurt, that everybody was calm," one passenger on the train reflected. "It's just an inconvenience as opposed to something worse."

"Everyone was a little unhappy that their days were clearly going to be messed up, as mine is right now, but everybody maintained their composure, everybody was calm, the Amtrak people did their job," the passenger continued.

The Long Island Rail Road canceled 29 trains scheduled during the evening rush.

Delays eased in time for the evening commute, though answers as to what happened will take longer to find.

A team of investigators from the Federal Railroad Administration arrived on the scene at Penn Station on Friday to begin piecing together what went wrong.

Photo via Twitter user @THEJordanGeary