Phillip Henderson and his two sons were lucky to walk away unscathed after finding a live grenade.
The Orange family decided to take a trip to Bathurst's Denison Bridge on Sunday to test out Mr Henderson's new Christmas gift - a magnet with 3,500 pounds worth of pulling pressure.
"We were just pulling in rivets and stuff from the bridge," he said.
"We brought in some metal parts and saw this egg looking thing and it was heavily corroded."
Little did they know that it was in fact a grenade.
"I wanted to throw it up and make it crack to see what was magnetic about it," son Ethan Walraevens said.
"We kept throwing it at the ground and then some of the stone fell off and we saw the little grid on it and dad decided to call the police and I started running."
Chifley Police District duty officer acting Inspector Peter Foran said Australian Defence Force staff attended overnight, took possession of the device, and safely destroyed it at about 6am on Monday morning.
He said the incident was a reminder to the community that people need to contact the police if they ever come across something suspicious.
"The message is if people find suspicious devices, be aware that it could still be active to some extent, so call the police and leave the device where it is," he said.
Mr Henderson said they will continue to magnet fish, but will try their luck somewhere else.
"Watching it and hearing the thuds, and knowing that each thud could've been our death, that's when it really kicked in," he said.
"We aren't going to play with fate again, so we're moving on to a different lake."