Police believe NASCAR driverJimmie Johnson’s mother-in-law Terry Janway shot and killed her husband Jack Janway and their grandson Dalton late Monday night at the family’s Oklahoma home, PEOPLE confirms.

Terry, 68, was found dead inside the residence along with her husband Jack, 69, and their 11-year-old grandson Dalton, police tell PEOPLE.Terry and Jack are the parents ofJohnson’s wife, Chandra.

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Jimmie Johnson

“Please tell me this isn’t really happening please god someone,” Marianne Janway, Johnson’s sister-in-law, posted on Facebook around midnight on Monday.

Muskogee police officer Lynn Hamlin tells PEOPLE the department received a 911 from a woman they believe to have been Terry, “who stated that there was a disturbance and someone had a gun and then hung up” the phone.

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When officers arrived shortly after 9 p.m., they found an individual laying dead in a hallway of the home and then heard another gunshot go off inside the house.

The department says its officer then found two more bodies in another location in the house. TMZ first reported the news Monday.Their deaths are being investigated as a murder-suicide and police say Johnson’s mother-in-law, Terry Janway, is believed to be the primary suspect.

“Additional information will be released if it becomes available,” the department said.

Jack Janway worked as a chiropractor in Muskogee. He and Terry are the parents of Chandra Janway, who married Johnson in 2004.

“It was traumatizing to find out that a long-standing family who had made so many contributions to our community were involved in this type of incident. It was even more bone-chilling to find out there was a child involved,” Muskogee Mayor Marlon Colemantold local Fox 23 News. “I knew Dr. Janway. Dr Janway has worked on me, we’ve been acquaintances for a very, very long time since I’ve been in Muskogee. Just knowing that it was him and his family took a different toll on me.”

The district said counselors would be available for students, families, and employees.

source: people.com