 And keep it right here on WTOP. We'll have your full weather forecast in just a few minutes along with traffic and weather on the 8th. Well, just about this time yesterday, more than 100 firefighters were working to put out a huge apartment fire in Southeast. Now this afternoon, we're learning what caused the fire. DC Fire and EMS tell WTOP it started when young people were flying with fireworks, were playing with fireworks, and they went off on a second-story balcony.