FLEMING ISLAND, Fla. -- A Clay County woman called 911 early Tuesday morning to report finding her husband and two children dead in what investigators believe was a double slaying and suicide.

Clay County Sheriff's Office Sgt. Dan Mahla said it appears that 49-year-old Jerry Whitelaw shot his 16-year-old son, Kevin, and 11-year-old daughter, Katie, inside their home on Grande Oaks Way in the Margaret's Walk subdivision just after 6 a.m. before turning the gun on himself.

Mahla said they believe the two children were killed in their sleep, then Whitelaw shot himself while his wife was in the shower.

"It has the appearance of being a murder-suicide," Mahla told WJXT-TV in Jacksonville. "Anytime it's involving children, it's devastating."

Grief counselors were available at the two children's schools: St. Johns Country Day and Grace Episcopal Day School. Dana Whitelaw also works as a secretary at Grace Episcopal.

"Our prayers are with the entire family," said the Rev. Kurt Dunkle of Grace Episcopal. "In times like this, it is only God that you can rely on and who will be there to pick up the pieces."

Court records show Dana Whitelaw had filed for divorce in August. While the sheriff's office had no record of previous police calls to the home, Mahla said, "There were some domestic issues."

Deputies continued to gather evidence at the home in the gated community off U.S. Highway 1 just north of Green Cove Springs.

This case joins the ongoing investigation into the disappearance and slaying of 7-year-old Somer Thompson, a recent double slaying at a Fleming Island nightclub and other high-profile crimes. The sheriff's office of this bedroom community of Jacksonville admits it is being stretched.

"I think our whole agency is maxed to the limit right now," Mahla said. "Thank goodness that we've had the Federal Bureau of Investigation, the Florida Department of Law Enforcement, the United States Marshals, NCIS and a lot of our neighboring agencies have come down to help us at this time."