SAN DIEGO (CBS 8) - Investigators are still working Friday to figure out what sparked an apartment fire in Serra Mesa.

An apartment fire erupted Thursday night in Serra Mesa, forcing dozens to escape out of their apartments.  

The fire broke out in the 3400 block of Ruffin Road. 

Michael Tran lives next door to the apartment where the fire started. He said he was watching Netflix as the fire began. 

"I started seeing smoke come through my door. I started backing up and yelling fire. People started coming out and yelling can someone call the fire department," said Tran. 

Tran and two of his neighbors tried to contain the flames with a fire extinguisher, but were pushed back by the intensity of the fire. 

Firefighters credit them for a quick response. 

"You could hear the windows start shattering because it was getting really intense and the fire was getting bigger," said Tran. 

According to firefighters, the man who lives in the apartment was not home at the time of the fire. 

Adjacent apartments were not damaged and firefighters said residents were able to return home Thursday night.