Vernon fire: Visuals capture heavy smoke filling the sky, flames engulf commercial building | Watch

The Los Angeles County Fire Department is responding to a second-alarm fire at a commercial building in Vernon after flames broke out on Thursday afternoon. Firefighters were called to the scene just before 3:20 p.m. at the 4600 block of Hampton Street.Vernon fire: Visuals show heavy smoke, flames engulf commercial building | WatchThick smoke and large flames could be seen rising from the building as crews worked to control the fire. The cause of the blaze has not been confirmed, and there has been no immediate word on injuries.Images shared by the Los Angeles County Fire Department showed firefighters tackling the fast-moving fire from outside the building.Vernon Fire grows to three alarmsAs crews continued their response, the fire was upgraded from a second alarm to a three-alarm incident. Firefighters used around 10 handlines and ladder pipes to pour water onto the burning building while working to stop the flames from spreading.Officials said the fire appeared to be contained to a single commercial property in Vernon's industrial area. The building involved was identified as the Alcon Transport Company, a trucking business. Nearby train tracks behind the property were shut down while emergency crews battled the fire.Warehouse destroyed in Vernon fireAerial footage from the scene showed thick black smoke rising high into the sky as large flames shot through the roof of the building. By the time firefighters gained better control of the blaze, at least one building had been destroyed.A second nearby building also suffered some damage, but firefighters were able to prevent the fire from spreading further through the industrial complex. Emergency crews remained at the site, checking for hotspots and continuing suppression efforts.Cause of Vernon fire unknownFire officials have not said what started the blaze, and investigators are expected to examine the site once it is safe to enter. Authorities also have not released information about possible financial losses or whether anyone was inside the building when the fire began.Firefighters said they were making steady progress as operations continued Thursday afternoon. Road users and businesses in the area were advised to avoid the scene while emergency crews completed their work and investigators prepared to begin their assessment.