A police dog died Friday after being left in a hot patrol car by his handler, Madison County Sheriff Phillip Morgan said.

Deputy Jonathon Cornelison is on paid administrative leave while an investigation is being conducted into the death of the 5-year-old dog named Lina, Morgan said.

The investigation is being conducted by the sheriff's office in Washington County, which is just west of Madison County.

"It was a bad accident," Morgan said. "It wasn't done on purpose."

Morgan said the Madison County sheriff's office had the dog for three years and it was their only K-9 officer, which is another term for police dog.

"We got lots of drugs with her," he said.

Morgan said he hasn't spoken with Cornelison since the dog died. Cornelison reported the dog's death to Sgt. Russell Alberts. Cornelison has worked for the sheriff's office since 2007.

Morgan said the dog was left in Cornelison's car while it was parked at his residence.

"I don't know exactly what happened," Morgan said.

The sheriff said he doesn't know if the dog will be replaced. Morgan isn't running for re-election, so the county will have another sheriff in January.

Metro on 09/15/2016