TULSA, Oklahoma - A hazmat situation forced dozens of people to evacuate an east Tulsa Apartment Complex Friday afternoon.

The source of the flames was one thing firefighters say you're not supposed to throw away.

Things slowed down Friday night at the Lakeside Apartments, where - earlier in the day - the air filled with potentially harmful fumes turning a trash fire into a Hazmat situation.

"It smells really bad really,” said resident Miguel Colin. “I was close to there and they said go back from there because it's all smoky and it's going to be bad for you."

Colin and around 40 residents that live at the Lakeside Apartments were forced to evacuate by firefighters. He said he came home to find a mess outside his door.

“I was coming from the store and I saw all this smoke and cars so I didn't know what was happening," he said.

Firefighters said it all started when the garbage truck picked up chlorine tablets during one of its stops, and when the tablets got in with the rest of the load it reacted.

"It's an oxidizer, so mixing that and putting a piece of paper, cardboard, a towel, could start a fire," said TFD Hazmat Coordinator, Paul Ator.

A fire with potentially toxic fumes is a hazard, and makes putting out the flames that much more difficult; but hazmat crews said the whole thing could have been avoided.

“They shouldn't throw away chlorine tablets, they should be dealt with. I mean we have the household pollutant collection twice a year, they will accept those at that point, so you shouldn't throw them in the trash. They are an oxidizer and they will react and cause a fire," Ator said.

It's a simple mistake that created a big, toxic mess and kept people out of their homes, waiting.

"They are doing what they have to do, so I'm just waiting until it's safe for everybody," said Colin.

Hazmat investigators said they are still trying to figure where the chlorine tablets were picked up.

Apartment management opened up the clubhouse for people to stay while crews cleaned the area.