First arriving units found heavy flames on the third floor extending through the roof of the building.
Prince George's County Fire and Emergency Medical Services spokesperson Mark Brady said four people were rescued from a second-floor balcony with the use of a ground ladder and a second alarm was sounded.
It took firefighters 45 minutes to put out the flames and Brady said there were no injuries.
The cause of the fire is under investigation and Brady said the blaze caused about $250,000 is damages.
Ten adults and seven children have been displaced from six apartments and they are being assisted by the apartment's management, Brady said.
Republished with permission of WUSA-TV.