DULUTH – Fire officials are investigating a fire that destroyed a large homeless encampment underneath Interstate 35 in Duluth on Monday night.

Smoke billowed from underneath the roadway near the Mesaba Avenue exit about 6 p.m. Firefighters removed several propane tanks, one of which had released propane, worsening the fire, according to a news release from the city. Fire blazed through several areas underneath the interstate.

Authorities did not find anyone in the area or anybody injured. A city spokeswoman said they are not sure how many people have been living there, but fire officials on the scene said it was one of the biggest encampments they have seen.

"Firefighters were challenged by the dangerous space and unsafe conditions due to drug paraphernalia and multiple sources of fuel including propane and gasoline," Assistant Fire Chief Dennis Edwards said in the news release.

Crews extinguished the blaze in about 80 minutes. The Duluth Fire Marshal's Office is investigating.

Jana Hollingsworth