An estate sale purchase in Austin, Texas, became a potential public safety hazard this week, when one patron’s box of items was found to contain World War II-era explosives, police said.

Officers responded to a call Tuesday from a local resident who had discovered what appeared to be grenades dating back to the war among the contents of their estate haul, according to the Austin Police Association. A police bomb squad confirmed the grenades were live and active, meaning they contained explosive material and could potentially denotate. 

Squad members were able to seize and remove the devices, while officers “quickly secured the scene, set up a perimeter, and kept neighbors safe,” the police association said, praising the bomb squad for their expertise as well as their “steady nerves.”

“Handling 80-year-old explosives with unknown stability is dangerous, precise work, and they do it with the professionalism this city counts on,” the association said.

Police said the situation should serve as a reminder to refrain from touching or moving military ordnance, including grenades, shells and mortar rounds, even it appears to be inert. Anyone who happens upon such a device should allow trained professionals to deal with it, authorities said.

Finding unexploded military ordnance in stockpiles of vintage belongings isn’t unprecedented. According to the FBI, some families of U.S. war veterans have discovered the dangerous “souvenirs” in their loved ones’ possessions, with most of the devices dating back to World War I, World War II, the Korean War, the Vietnam War or the Gulf War.

Last year, a young boy discovered a live hand grenade, which also originated during WWII, on his family’s property in central Washington. Authorities said at the time that the 3-year-old wasn’t harmed, and bomb technicians were able to remove and dispose of the device in a rural area outside of the town where his family lived.