The man was rushed to the hospital moments after the major explosion inside his apartment. There was no word on his condition.
"He was using chemicals with marijuana to extract THC. It's some term that they use like honey butter," said Los Angeles County Fire Department Inspector Quvondo Johnson.
There are many how-to videos posted to YouTube on how to make honey butter or honey oil. They explain how to use highly flammable butane to extract oils from marijuana. The finished product is a very concentrated form of pot.
"Whatever he was doing it had a flash and it blew out the windows," said Johnson.
"I had gotten home from work, I got situated and I heard a big boom, and I just thought it was a car accident happening down the street," said witness Scott Backman.
The explosion happened inside a courtyard and never started a fire, but it did blow out several walls.
"There's debris from the wall exploding, there was dust everywhere. Pieces of the wall everywhere. I saw a couple of neighbors running around," said witness Nick Rafferty.
The explosion displaced dozens of residents for much of the evening. Most of them were allowed back in by 11 p.m., however investigators continued to examine the structural integrity of several apartments.