A deadly fire ripped through a building in South Los Angeles early Saturday morning, and authorities believe that the structure, which appeared abandoned, housed a possibly illegal “cannabis operation.” 

According to the Los Angeles Fire Department, firefighters responded to 832 East Manchester Avenue in South L.A.’s Green Meadows neighborhood at 1:15 a.m. regarding a car fire that was quickly upgraded to a structure fire. 

The building was heavily involved with flames by the time crews arrived and the roof had collapsed, LAFD confirmed. The firefight was made harder by a marijuana grow operation inside the seemingly abandoned structure. 

“We can’t say for sure because we don’t know exactly what permits they had…but we did not see any placarding from the outside that would indicate that this was a cannabis operation, which they should have had,” said LAFD Captain Adam Van Gerpen. “There are multiple different types of chemicals that they use to do this and some of them could be explosive…and have deadly results.” 

After more than 110 firefighters extinguished the fire in just over an hour, first responders found a man dead inside the building, law enforcement officials said. 

“Their systematic search will continue to assure no other victims were inside the seemingly abandoned building that proved to contain a cannabis operation,” LAFD said.  

The exact cause of the fire is unknown. 

Manchester Avenue at McKinley Avenue will remain closed while authorities conduct their investigation.