NORTH RICHLAND HILLS, Texas -- A nightmare unfolded inside a home decorated for the holidays Saturday morning in the 7400 block of College Circle South.

Police say that's where a father fatally shot his children, then turned the gun on himself. His son was nine, and his daughter was five. Police say, their mother was in the home, and called 911.

"It's just so tragic, the holidays are very stressful for everyone, but this is such a tragedy," said Carissa Katekaru, North Richland Hills Police spokeswoman.

"Two kids right here at Christmas time, that's tough," said neighbor Karen Banner, who woke up to ambulances and police cars next door.

"I just feel sorry, sorry for the whole family, it's terrible," said a neighbor, Denise Albino.

The main question police are trying to figure out is "why?" They're interviewing the kid's mother to see if they can piece anything together.

"It's very, very hard on us to work these kinds of cases so close to the holidays. Many of us, we have children too," said Katekaru.

Police say they have no history with the family, at least in North Richland Hills. Neighbors say the family just moved in a few months ago, and the kids quickly became a regular sight.

"I've seen the little kids playing soccer out in the front yard," said Banner. "I never did see the dad, I only saw the mother with the little kids, picking them up, taking them to soccer games."

"I never saw the man. Never," said Albino. "I really thought she was a single parent."

Police have not yet released the names of the father and children, and the case is still under investigation.

This story will be updated when more information becomes available.