This just in !
Smoke seen coming from building in Los Angeles' Arts District; witnesses report hearing explosion - @juanito_blanco
Explosion reported in Arts District in Downtown Los Angeles - @GoodBerger
Emergency crews responding to reports of explosion in Los Angeles' Arts District; smoke seen in area - @juanito_blanco, @dyannecano
Emergency officials block off scene of reported explosion in Los Angeles' Arts District - @juanito_blanco
Witnesses report buildings shaking after sound of explosion, smoke in Los Angeles - @melisande_8
Los Angeles Fire Department confirms explosion, fire near apartment building in city's Arts District; cause of explosion not immediately known
Officials say explosion that shook Los Angeles' Arts District occurred at building under construction - LA Times