Video shows a large fire at a building in Houston. 

The report comes as Houston is dealing with historic flooding caused by Hurricane Harvey. FEMA Administrator Brock Long said that 450,000 people could seek disaster assistance due to damage caused by the storm. 

The fire at the Lone Star Legal Aid offices in Houston comes after witnesses reported an explosion, according to Houston-based KTRK-TV. 

It is not immediately clear if there were any injuries or how the fire began.