The Long Island Rail Road is expected to have a normal evening rush hour after a three-alarm fire that left two firefighters with minor injuries early Tuesday morning disrupted the commute, according to transit officials.

The fire broke out at a construction site at the western concourse of the LIRR just before 2:30 a.m., FDNY officials said. More than 150 firefighters responded to the three-alarm fire, which the FDNY said was under control by 5:22 a.m.

The fire marshal determined the fire was an accidental electrical fire that broke out in an area with temporary wiring used to light the construction site, an FDNY spokesman said.

A video posted on Instagram showed flames rising up to street level. Leonard said the fire broke out in the LIRR's expansion under the James A. Farley Post Office, where Moynihan Station is being built.

The fire blackened walls of the construction area and left the smell of smoke by the 33rd Street entrance for the A, C and E trains.

Without full access to tracks, some LIRR trains were diverted or canceled out of Jamaica, while A, C, and E trains skipped Penn Station until 6 a.m., according to MTA officials. At 8:30 a.m., there were 5-10 minute delays to trains going into Penn Station.

Trains were back to being on or close to schedule at 9:30 a.m. Trains were back to being on or close to schedule at 9:30 a.m. The MTA avoided problems during the evening commute when it regained access to the tracks and the west side yard where trains are stored, according to LIRR officials.

While many of the surrounding roads had reopened by 8 a.m., West 33rd Street between 8th and 9th did not open until 11 a.m.

- With Gary Dymski