34 people injured, some NYC subways suspended after train derails

A New York subway train derailed in Upper Manhattan on Tuesday morning, halting service on four busy lines. Thirty-four people suffered minor injuries, Fire Commissioner Daniel Nigro said at a press conference.

The MTA apologized on Twitter for "service disruption" the derailment caused. Officials declined to comment on the investigation. Chairman Joe Lhota said MTA is investigating the cause of the accident, but so far it does not appear to be a failure of equipment or tracks.

All disabled trains had been evacuated by noon, according to MTA, nearly two hours after initial reports of the derailment.

Passengers shared photos and messages that described a chaotic moment when an A train crashed into a wall at 125th Street in Manhattan.

Service was halted on the A, B, C and D trains, major lines running through Manhattan and into neighboring boroughs. The train that derailed was badly damaged.

The last subway derailment was in 2015, when a G train went off the tracks in Brooklyn. A year earlier, an F train derailed in Queens. No one died in either accident, though some were injured.

New Yorkers are no strangers to frustration with the subway system. Brooklyn residents expressed outrage last year when the MTA announced it would close a tunnel that carries the L train for 1½ years starting in January 2019.

Amtrak has also been a target of criticism in the New York area. One of its Acela trains derailed as it left New York's Penn Station in March, prompting Amtrak to expedite plans to repair the train station.

Penn Station is a major transportation hub in New York, serving Amtrak, New Jersey Transit, the Long Island Rail Road and MTA subways. Amtrak, NJ Transit and the LIRR will modify their schedules when work starts July 10. The project is expected to take years.

WATCH: Elon Musk's new underground tunnel project will transport cars at 125 mph