UNION COUNTY, Tenn. (WATE) — Loved ones are mourning the loss of a deputy killed in a crash while investigators work to determine what caused it.

Union County Sheriff’s Deputy Matthew Kirrman was killed just after midnight Sunday morning when his patrol car left the road, smashed through a barbed wire fence and came to a rest in a field.

Authorities are working to determine what led to the crash. Meanwhile, Kirrman’s loved ones are mourning his loss.

Deputies Andy Oliver (left) and Matthew Kirrman (right); courtesy of Greg Pulliam

Deputy Andy Oliver met Kirrman one year ago while at the academy. Before coming to Union County, he served in the Knox County Sheriff’s Office.

Once Kirrman joined the Union County Sheriff’s Office, the two became partners on the force.

“When he graduated, we figured out he was coming to our shift, so we were excited, he was excited,” said Oliver.”I told it to his face, I tell everybody, there’s not a door I wouldn’t go through that I wouldn’t feel confident in Kirrman having my back.”

Their bond was the result of hours spent inside patrol vehicles, responding to calls, workouts, and off-the-clock shopping trips.

“I’ve never had a better friend,” said Oliver.

Early Sunday morning, Oliver got the call and was told his partner had been in a wreck.

“He informed me of what was going on at the time,” explained Oliver. “What he knew was going on. Course, I jumped out of bed, grabbed my wife, we put our clothes on and we started that way.”

Hours later, Oliver learned his friend didn’t make it. He along with many others is mourning Kirrman’s loss and bracing for the impact his absence will cause.

“Didn’t matter who you are, what you were, he would always talk to you and talk to you with respect,” Oliver told WATE.

Deputies Andy Oliver (left) and Matthew Kirrman (right); courtesy of Greg Pulliam

While Oliver prepares to say a final goodbye to his friend, he is also saying thank you.

“I’d thank him for all the memories that we got to share. And I’d thank him for being such a good friend.”

A GoFundMe has been created to help Deputy Kirrman’s wife and his family. The family hopes to raise $20,000. To visit that account, click here.

According to funeral arrangements announced by Click Funeral Home, Inc. and shared by the Union County Sheriff’s Office, Kirrman’s body will lie in state at St. Nektarios Orthodox Church, 11525 US-321, Lenoir City starting at 6 p.m. on Friday, October 14 until 10 a.m. Saturday.

The church will be open through the night for visitation. The funeral will be held at 11 a.m. Saturday at the church. Kirrman will then be interned at Woodlawn Cemetery in Lenoir City.