Fortunately everyone got out of the home safely although no smoke detectors went off.
The fire started around 4 a.m. at a home in the 600 block of East Boulder Street.
Firefighters say someone put out a cigarette or cigar, which started a fire in the wall of the home.
Ten fire engines and at least 40 firefighters were at the home. But the sound of smoke detectors were nowhere to be heard.
"I smell smoke. So I got up and check my apartment, then I went outside and saw the fire. I started screaming for them to wake up and I started knocking on their doors," said Joseph Herndon, who says he acted as the fire alarm. Herndon got everyone out of the house safely. Residents were living in three apartments inside of the home.
Although the fire was very close to Herndon's cottage, his alarm didn't go off. Fire crews say that's expected, as most smoke alarms are designed to detect fires inside your house.
"It was right by my windows and my windows are open. So you would think that the fire alarm would go off. It didn't though," said Herndon.
Inside of the large home fire crews said they found only one fire alarm, without a battery
"There was a working smoke alarm in the cottage, but that is a separate building from the house. We did find a smoke alarm with the battery removed from it and that's very concerning for us," said Steve Oswald, with the Colorado Springs Fire Department.
Firefighters say you need a fire detector near every bedroom.
"Probably one smoke alarm for three different apartments is below adequate. The property owner is responsible for having smoke alarms in the home, prior to the home being leased out. Once the lease is signed, it's then up to the renters to make sure it's maintained," said Oswald.
In the end, fire crews say residents are very lucky that their neighbor has a good nose.
"Based off the way the flames were going with the fire, it could have been a lot worse if I had not did what I did, when I did it. So I'm just thankful everyone got out safely," said Herndon.
Six people were displaced after the fire.
Red Cross is helping the families to find places to stay.