Calgary Fire Department crews responded to the northwest community of Ranchlands following a fatal fire on Sunday morning.
Around 2:30 a.m, crews were called to an apartment complex in the 6000 block of Ranchview Drive N.W.
According to CFD, there was significant smoke and flames coming from the second floor of the building when fire crews arrived.
Crews were able to contain the fire to the second-floor suite.
One man was found dead inside the suite. The cause of death is under investigation.
Twenty people were evacuated from the building and 10 remained evacuated around 4:30 a.m. Sunday.
CFD and police were on scene and expected to be throughout most of Sunday.
The cause of the fire has not yet been determined.