Penn Station was evacuated and train service was halted for about three hours after a fire erupted in a transformer beneath the East River, causing chaos for thousands of travelers.
The fire department said it responded to a transformer explosion and fire on tracks used by Amtrak in an East River tunnel in the early afternoon. Five people were taken to the hospital for smoke inhalation, but there were no serious injuries.
The cause of the transformer blast was under investigation.
The fire forced Amtrak, the Long Island Rail Road and New Jersey Transit to alter routes.