GARLAND, Texas -- The Garland Fire Department is investigating what caused a fire that killed four people, including two children, early Saturday morning.

The victims have been identified as 41-year-old Lorenzo Castillo, 29-year-old Ana Castillo, Ana's 5-year-old daughter, and the couple's 2-year-old son. They were visiting from Bridgeport, Texas and staying with relatives over the Thanksgiving holiday weekend.

Just after 1 a.m., firefighters were called to a home at 1416 Williams Drive, off South Garland Avenue and just north of West Miller Road.

The house was engulfed in flames with people still inside as crews arrived.

Neighbor Anthony Cruz said the man living at the home tried to go in for the rescue.

"The family was running towards my house and the husband was trying to go in and rescue them while I was knocking on the window," said Cruz.

A neighbor called 911 and firefighters also tried to save those inside once they arrived but were unable.

NOV. 25, 2017: Two adults and two children were killed in a house fire in Garland.

There were a total of nine people inside the home at the time of the fire. Five were able to escape, including a third son of the couple.

Ashley Snead said the family living at the home is liked by all their neighbors and family gatherings were not uncommon.

"They are always having families over for get-togethers and just really enjoying life," she said.

Officials say the family of four was sleeping in a bedroom in the back of the house when the fire broke out inside an enclosed patio.

While the fire doesn't seem to be intentional, the cause is under investigation. The owner of the home told officials they heard a "popping noise."

The home had one smoke detector in the hallway, but it's unclear if it was working.

A neighbor across the street called 911 to report the fire.