The incident was reported around 9:15 a.m. Wednesday in the area of Lehigh Avenue and Richmond Street along the train tracks.
Firefighters responding to the scene found a tanker leaking gasoline from the top.
The tanker holds 30,000 gallons of gasoline, though there was no immediate word as to how many gallons leaked.
The situation was declared to be under control about an hour later.
However, the train itself is still stopped on the tracks while cleanup work continues.