Fire crews were called out to the area of Peach and Liberty avenue at around 10:30 Saturday morning.
[Ads /]
Officials say the fire started due to some unattended cooking oil on the patio.
The flames spread from outside the apartment into a common attic space and a second unit.
Authorities are reminding the public to be careful during this time of year.
"Make sure we don't leave that cooking, unattended stoves, or butane torches, or cooking or turkey fryers, barbecues unattended heat sources can easily cause fires, which then much of the case here, can spread not only to your unit but into joining units," Fresno Fire Department Battalion Chief Lawrence French said.
[Ads /]
It took about 40 firefighters to contain the blaze.
Two units sustained heavy damage, while another unit had minimal damage.
Crews say it's unknown when the residents will be able to return.