Three men with a sledge hammer smashed their way through a King of Prussia jewelry store on Wednesday, grabbing what they could before running out of the store.
Officials tell NBC10 the three masked men walked into the store and threatened the security guard with the small sledge hammer. One of the thieve smashed a display case, while the other two swiped numerous watches from the cases.
Investigators said the whole thing lasted less than 20 seconds.
No one was hurt. Police have not yet determined the value of the goods taken.
There have been previous robberies at this store.