Construction workers discover live explosives underneath Treasure Valley bridge

Idaho construction contractors ran into something scary on Halloween as they conducted maintenance repairs on the Idaho 45 bridge over the Snake River: two unexploded military ordnances.

According to an Idaho Transportation Department press release, divers working on the bridge repairs dove into the river to inspect the base of a bridge pier on Oct. 31. While underwater, they discovered the first ordnance. The contractor contacted the Canyon County Sheriff’s Office, and a bomb squad arrived from Nampa Police Department to remove the device.

In a phone interview Tuesday, Mountain Home Air Force Base officials said the devices were pre-1970s artillery rounds that did not originate from the base.

“The Mountain Home Air Force Base received the device and safely detonated it off-site,” ITD said in the release.

The next day, the second ordnance was found nearby. Both devices were about 20 feet underwater. The construction crews again halted work and contacted the Air Force base’s explosive ordnance device unit. The EOD unit determined the device wasn’t an immediate risk to boaters or bridge travelers, so removal was delayed a week until Nov. 9.

A Navy dive team removed the second device and swept the area for any additional ordnances, ITD said. The bridge was closed during that time. No other devices were found in the immediate area, but ITD said it will continue to sweep around the site before maintenance continues.

This story was originally published November 13, 2018 at 3:07 PM.