Nearly 4,000 commuters were evacuated from two subway lines Wednesday after a fire broke out near a Brooklyn station.

MTA officials say a piece of wood that supports the rail near the DeKalb Avenue station platform caught on fire. Fire officials say the fire appears accidental and there is no indication of malicious intent.

Subway service on the B and D lines was temporarily suspended after the fire. The power was turned off while people evacuated the subway cars. More than a dozen people, including firefighters, were treated for smoke inhalation. Service was restored by about 9:30 p.m.