Authorities evacuated Birmingham, England's New Street Station and trains were held after a grenade was found on a platform. Turns out though, the "grenade" was actually a weed grinder. After about two hours, operations resumed. From the BBC News:
"The item has now been assessed by specialist officers and is no longer being treated as suspicious," British Transport Police said.
Birmingham New Street is the busiest station outside of London and the security alert saw commuters turned away, while others were left stuck on trains outside the station.