LOS ANGELES An explosion in downtown Los Angeles injured 10 firefighters Saturday, and more than 200 others rushed to the scene as the flames spread to several buildings. The condition of the injured was not immediately known. My thoughts are with our brave @LAFD firefighters," Los Angeles Mayor Eric Garcetti tweeted. Los Angeles Fire Department spokesman Nicholas Prange said the firefighters entered the building, and there was nothing unusual until the explosion occurred. It was not immediately known what was in the building or what caused the explosion.