An apartment fire in this Central Valley town killed five people early Saturday, including three children.

Firefighters found the bodies of Derik Faubion and his fiance, Michell Mattison, both 19, and their 2-month-old daughter, Hayden Allison Faubion. Two siblings of Mattison, Lexus May Bisnar, 4, and her brother Ariel Nel Bisnar, 2, also died.

Investigators have not determined a cause. Lemoore Police Chief Kim Morrell told the Fresno Bee that foul play was not suspected.

The building had shingle roofs and plywood siding, said Ted Schlosser, assistant fire chief for the Lemoore Fire Department.

"It didn't take it long to spread, Schlosser said. "The whole roof was fully engulfed when we got here."

Schlosser said Lexus and Ariel's mother had left the children with Mattison at the apartment for a few hours. When she came to pick them up, the kids were asleep, so she decided to let them stay overnight.

Authorities responded to the fire shortly after 1:30 a.m. Saturday. Sirens jarred neighbors out of bed.

"When I walked out, all I saw were flames," said Lacey Mayhew.

Firefighters discovered the bodies after they put out fire, which destroyed nine of the 23 apartments in the complex.

Another person was taken to a hospital with smoke inhalation, officials said.

Derik Faubion's mother, Bernadette Faubion, said her son and Mattison were high school sweethearts who had moved into the apartment complex just one month ago.

"They were going to save money and get married," she said.