A freight train has derailed in Washington DC spilling hazardous liquid, emergency officials say.
At least nine cars of the CSX freight train overturned near Rhode Island metro station early on Sunday.
The DC fire department said sodium hydroxide, also known as lye and caustic soda, is leaking from one car.
There would be no evacuation of nearby residents, it added. No injuries have been reported. The cause of the derailment is unclear.
Sodium hydroxide is a corrosive chemical that can irritate and burn the skin and eyes.
According to the US Centers for Disease Control, while sodium hydroxide is not combustible contact with moisture or water it may generate enough heat to ignite combustible substances.
CSX said the train had three locomotives and a total of 175 cars – nearly half of them empty, the rest carrying mixed freight.