A Prince George’s County firefighter sustained minor burn injuries Friday night battling a fire at a Riverdale area duplex, authorities said.

The blaze broke out about 9:30 p.m. at a home in the 6000 block of Longfellow Street, authorities said, adding that firefighters arrived to find flames coming out of the second-story windows.

The fire at a duplex in the Riverdale area caused about $100,000 in damage. (Jim Davis/COURTESY PRINCE GEORGE'S COUNTY FIRE/EMS DEPARTMENT)

Fire officials said that one half of the duplex was vacant and that the occupants of the other half, where the fire started, were able to escape unharmed. It took firefighters about 20 minutes to put out the fire, which caused about $100,000 in damage, authorities said. The firefighter who sustained burn injuries was treated and released from the hospital, they said.

Officials said an adult and a child were displaced. Investigators are still probing what sparked the fire.