Des Moines police said they may know how an apartment fire started early Monday morning.According to police, the fire started inside of an apartment at Gray's Lake Apartments on Fleur Drive when an occupant "attempted to light a bug on fire on a futon."It "lit up like a tinderbox," according to police. Several people have been displaced after the fire. Emergency crews had to block off part of that main road while they battled the flames.Shelby Spieker was allowed to go back up to her apartment around 3:30 a.m. to get some things but when she walked in, she was devastated.Ash was everywhere, her ceiling had fallen in and everything was soaked in water."It looks like a teddy bear stuffing factory exploded everywhere and then they soaked it in an Olympic sized pool. I don't know, it's so bad," Spieker said.No one was injured in the fire, but smoke filled the entire building, so even though only four apartments had any damage, they are taking extra precautions and evacuating three other units because of all the smoke that filled the building.Fleur Drive was shut down for a few hours, but emergency vehicles left around 3 a.m. and they were able to reopen the road.The fire started about midnight. That's when Spieker got the call at work that her home was on fire."The building on fire and I could not have imagined those would be the words coming out of his mouth," Spieker said. "He called me back five minutes later and he's like it's coming from your apartment and I'm like, 'what do you mean it's coming from my apartment, I haven't even been up there, what's going on.'"The Red Cross is at the scene trying to set victims up with hotel rooms and other places to stay.The fire department told KCCI there are 38 units inside the building that burned, which means dozens of people have been standing out in the cold all night. At least seven of them will be looking for a place to sleep.