FLEMING ISLAND, Fla. -- It was an especially shocking crime in a suburban community that seemingly happened with no warning.

Police said two children were shot and killed by their father who then turned the gun on himself Tuesday morning in Fleming Island.

Now, those who knew Kevin and Katie Whitelaw, the two Clay County children, are trying to find an explanation.

Messages of support were displayed outside Grace Episcopal Church on Wednesday, reading, "Our prayers are with the Whitelaw family." Katie, 11, attended Grace Episcopal Day School, and her mother Dana Whitelaw works there.

A sign at St. Johns Country Day School, where 16-year-old Kevin was a student and athlete, was also changed to show support for his family. The sign now reads, "We will always miss you, Kevin." Students at the school on Wednesday wore orange and blue because of Kevin's love for the Florida Gators.

Residents are struggling to understand how a father could kill his children and then commit suicide.

Jerry Whitelaw and his wife, Dana, were in the process of getting a divorce. The first papers were filed in late August by Dana Whitelaw.

The case file appears to be typical for a divorce. Dana asked for child support, alimony and their home so she could have primary custody of the children.

According to court papers, Jerry Whitelaw did not appear to put up much argument. The latest papers were filed several weeks ago, including a financial affidavit saying Jerry worked for Idea Integration in Jacksonville. The company said he no longer worked there.

Despite the failing marriage and his wife's request for the home, Jerry Whitelaw did continue living in the home with the family during the divorce process. Experts said that could have been a problem.

"It can be dangerous as obviously we found yesterday," said Sharon Youngerman, the executive director of Quigley House and an expert in domestic violence.

She was called to the scene Tuesday to try to comfort Dana Whitelaw.

"Obviously, when a couple is divorcing, there's a major strain on the relationship," Youngerman said. "So even in the best of worlds that can be very difficult."

But was that enough to lead to such a horrifying crime? Is it possible for a spouse to predict that something so tragic could happen?

"There's no way to really know for sure," Youngerman said. "I wish we did. I wish we did have a crystal ball because it would make it so much easier to reach out to those who are much more at risk."