DENVER (CBS4)– The legality of a marijuana grow operation is being investigated after an explosion that sent three people to the hospital.
“At first I thought it was gun shots,” said witness Cindy Gillmore. “When a boom happened, you could see a big ball of flame.”
Police and firefighters rushed to the building in the 1200 block of South Lipan Street where investigators said three people were extracting THC from marijuana using butane canisters.
The process is dangerous and has caused several similar explosions in Colorado and around the country.
Dozens of canisters filled with butane gas were found at the scene where the blast happened.
“The extraction process itself is not illegal once it’s permitted. There are a couple of variations where you can get a permit to do that but the operation they had going on here is definitely illegal,” said Denver Fire Department spokesman Mark Watson.
Two men and a woman were rushed to a hospital with second-degree burns.
Gillmore saw the victims as well as others who appeared to be running away, “Which gave me a really uncomfortable feeling because it seemed like, ‘Why are you doing that? What are you up to? What’s happening in there?'”
Fire investigators are trying to figure out whether the marijuana grow operation inside the building was legal. They found 36 marijuana plants inside. They said the building is not permitted or zoned to grow marijuana and it’s likely charges will be filed.
“It’s a fire code violation where you’re endangering not just property but people also,” said Watson.
The building was not damaged in the explosion.
Investigators will meet on Thursday to discuss their findings and what charges those burn victims could face.