2 WWII grenades found at CO lake in less than 24 hours (VIDEO)

Authorities are working to determine how two World War II era grenades landed near a Boulder County, Colorado lake.

The first was discovered by a couple after a man accidentally stepped on it Tuesday night. Against the advice of his girlfriend, Anthony Perkins picked it up, only to realize that it was heavy and likely still live. The couple called the police and the Boulder County Regional Bomb Squad dealt with the device.

But the following day, park rangers found a second grenade near the same location and once again, the bomb squad was called in.

Meanwhile, the park remains closed at least until Friday or at such time authorities can ensure that the area is grenade-free.

[ Fox 31 ]