MILTON — Authorities don’t know how a live hand grenade wound up on the ground on Creek View Court, but the discovery was made before 5 p.m. Friday.

A construction worker found the grenade while sifting topsoil onto a homeowner’s lawn, Saratoga County sheriff’s deputies said. The state police bomb squad determined that the grenade was live and took it away to properly destroy it.

Authorities said the grenade appeared to have been on the ground for a long time and they don’t know where it came from.