Last Thursday, a routine hike for two Portland, Oregon residents almost turned deadly.

While walking their dog in Forest Park, Mike and Jennifer Colbach came across a makeshift trip-wire blocking their path. Though they both became aware of the device in time to step over it, their dog did not. Luckily, the wire just went slack.

But, feeling unnerved, Mike Colbach decided to return to the park on Saturday to do some further investigating. He followed the trip-wire, made of a parachute cord, to a tree, where it had been rigged and attached to a three-quarter-inch in diameter pipe—open at one end, closed at the other. Colbach realized that if the device had not been faulty, a beer bottle would have swung down and struck the firing pin at the back of the device, unleashing the 12-gauge shotgun shell lodged inside the pipe toward where he and his wife had been standing. It was a homemade firing device aimed to shoot whoever tripped the wire.

Colbach immediately contacted a friend of his who works for the Metropolitan Explosives Disposal Unit. Later that day, the police dispatched a bomb squad to disarm the makeshift firearm. They are currently holding it as evidence, and are seeking to find the responsible party.

Though the Portland police told local news these situations are incredibly rare in rural areas, Colbach isn’t planning on returning to his favorite hiking path anytime soon. “I’m not going to the park for a while. I don’t want to trip the next one,” he told local newspaper, The Oregonian. “Why try to kill someone in broad daylight?”

The Portland police are asking that anyone with information contact them at (503) 823-4106 or via email at guntaskforce@portlandoregon.gov.