A Yavapai County Sheriff's Office volunteer is being credited with saving the life of a dog being dragged by a semi truck in Ash Fork, Arizona.

ASH FORK, Ariz. -- A tractor-trailer in Arizona was pulling more than the driver thought when he exited a gas station 50 miles west of Flagstaff, and the quick reaction of a volunteer saved a life.

The semi driver was heading to Interstate 40 on Sept. 8, but he'd forgotten to untie his dog from the trailer bumper.

The dog can be seen running to keep from choking as the big rig picks up speed in dash camera footage from the Yavapai County Sheriff’s Office.

The office employs volunteers to help with some patrol duties including traffic control and roadside assistance.

One such volunteer happened to be leaving the same gas station when he spotted the potentially deadly situation unfolding in front of him.

He immediately turned on his lights and siren and honked his horn, then drove alongside the truck and got the driver to stop.

The sheriff's office said the owner was grateful and thanked the volunteer for saving his pet's life.

"The driver was simply distracted and headed towards the interstate forgetting to unleash his dog," the Yavapai County Sheriff's Office wrote in a statement.

Typically, volunteers aren't supposed to use lights and sirens to stop a vehicle. But, deputies say using the siren to rescue a dog is definitely an exception.

No charges are being sought against the truck driver.

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