An investigation is underway outside of Dallas after police say a father shot and killed his two young kids before turning the gun on himself. 12 News has learned the family lived in Phoenix up until a few months ago.

North Richland Hills police were called by the mother of the children, Rachel Dawson, around 7:15 a.m. Saturday. She reportedly found her two young children and her husband dead.

"I met Rachel at a boot camp class and she would bring her kids, Luke and Bree, sometimes," said Rachel's former Wrigley Terrace neighbor Ariel Borg.

Borg and her kids became close with Rachel Dawson and her kids, 9-year-old Luke and 5-year-old Bree. Borg said something seemed off with Rachel's husband, Chris.

"He was very, very controlling of Rachel to the extent that after a certain point he no longer allowed her to be friends with us," Borg said.

A few months ago, the Dawsons left Wrigley Terrace and moved to Texas. The unthinkable happened inside their new home.

"We saw warning signs but I don't think anyone could have guessed that this would've happened. It shocked everyone," said Borg.

Rachel Dawson found her two young kids and her husband dead in an apparent murder-suicide.

Borg and many of her neighbors are having trouble coping with the fact that their friend has lost both of her children and wonder if they could've somehow prevented it.

"We saw warning signs but it's hard to know when to step in," said Borg. "I just feel like we should've done more."

Police in Texas are now trying to piece together how a father could take the lives of his own children. The investigation is happening a thousand miles away but for Borg and Dawson's former Phoenix community, it hits very close to home.

"This community is feeling that loss. Her family was our neighbor," said Borg.

Borg is hosting a candlelight vigil for the Dawson children on Wednesday at 6:30 p.m. It's being held outside her home and will be led by a pastor of the church the Dawson family attended while they lived in town.

Family members have set up a GoFundMe page to help Rachel Dawson with funeral expenses. If you're interested in donating, click here.