An Amtrak train derailed as it was leaving Manhattan’s Penn Station on Wednesday afternoon, causing delays for both Amtrak and NJ Transit commuters in the area and prompting road closures near the station, according to rail and New York City emergency officials.

A set of wheels on the train came off the tracks just south of the station around 2 p.m. on Wednesday, Amtrak said. Spokesperson Jason Abrams said part of the train was still on the platform, so passengers were able to get off safely and quickly.

By about 4 p.m., both Amtrak and NJ Transit were warning of delays of about 30 minutes in and out of Penn Station. Amtrak said customers on affected trains could call 1-800-USA-RAIL to change their train reservations to others with similar departure times, without incurring fees. NJ Transit said it would cross-honor tickets with its bus service and private carriers.

Earlier in the afternoon, New York City’s emergency notification system, Notify NYC, warned of traffic delays, mass transit disruptions and emergency activity near Penn Station. As of shortly before 4 p.m., a city emergency management spokesperson tweeted that FDNY operations near the station had wrapped up.

No injuries were reported as of mid-afternoon on Wednesday, according to NYC Emergency Management.

Midtown was already slated for several street closures and slow traffic while the U.N. General Assembly is in town this week.

This is a developing story and may be updated.