The fire started around 12:45 Monday night at the apartment complex on Walnut near Divisadero in Visalia.
One neighbor tried to save her, but the flames were already shooting from the window by the time anyone realized there was a fire.
Family members and friends say the 80 year old victim was a heavy smoker and several times Monday she even dropped her cigarette on her lap. Investigators have not released a cause, but many believe it may have been accidentally caused by smoking.
Kate Olson was independent and was still driving up until a few weeks ago. But neighbors say the past days she has had trouble getting around and only made it to her mailbox.
Early Tuesday morning, Chris Box heard a front window exploding and looked outside to see his neighbor's apartment in flames. He ran to get the keys from the manager and after unlocking several locks he got into unit one. While crawling around he was shouting Kate's name.
"There was a lot of glass breaking, a lot of fire," said Chris. "I could hear her in there for a minute, not too long after I got the door open, and I couldn't hear her anymore."
Chris got close to her, but wasn't able to reach Kate before he had to get out. "I tried to go in as far as I could breathe and once I got in and started breathing as far as I could go before I started breathing in smoke and at that point I just ran for the hose."
Rosa Rodriguez spent a lot of time with Olson over the past few years. She lived in the same complex and often visited her. They often reminisced about their youth and hobbies.
"When I went over there Sunday and I had my dogs there and she was sitting there on the sofa with a blanket," said Rosa. "And my dog sat next to her, my dog would not leave her and she kept on petting him and petting him. I was there for about an hour with her."
Fire investigators aren't releasing a cause of the fire, but it started near the area Kate was found in. Family members say it appeared she was trying to escape the flames when she was eventually overcome.
Firefighters say by the time they arrived, the fire was so involved, that when they reached the victim, it was too late.
Charlie Norman with the Visalia Fire Department said, "First initial attack crews forced entry and extinguished the fire performed a primary search, and found the victim in the living room of the residence."
It's unknown how Kate Olson died, whether she was overcome by the smoke or flames. Firefighters hope to pinpoint a cause within the next week.