GRANT COUNTY, Wash. -- Investigators said Grant PUD security personnel discovered an old pineapple-style hand grenade in the Columbia River Thursday evening.
Authorities said the grenade was found below the high water mark of the drawn-down Columbia River near the Old Vantage boat launch in Grant County about 6:00 p.m.
The WSP bomb squad responded and detonated the grenade, officials said. Local residents in Sunland Estates and Vantage may have heard the explosion.
The Grant County Sheriff’s Office said the grenade was a fragmentation style device of a style developed for use during World War II. The style was used by U.S. armed forces until the late-1960s.
The grenade was rusty and had apparently been in the river a long time, according to investigators. They were not sure how long it had been in the river bed or who put it there.
No one was hurt.