An emergency crew responded to the scene, in the 300 block of North Tacoma Avenue, at about 12:55 a.m. after receiving a 911 call about a carbon monoxide alarm going off inside the building, said Dale Vaughn of Central Pierce Fire and Rescue.
The crew found high levels of carbon monoxide and a smell of natural gas inside the structure.
Twenty-two residents were evacuated and additional emergency responders were called in as a Puget Sound Energy crew shut down the gas to the building.
An investigation found that the chimney from the boiler room had become blocked, sending gas fumes from the boiler into the building.
"You could smell it really bad," said David Pearson, who has lived in the building for the past 13 years.
The building was ventilated and residents were allowed back into the the building at around 2:30 a.m.
There is currently no gas heat available in the building, but all other utilities are available, Vaughn said.
No one was injured.