Firefighters got him out in 15 minutes. No harm done. But it can't be good for the reputation of Winchester safes that a trio of pre-teens picked the lock not once, but twice, according to this Telegram and Gazette article:
_Daniel [Jancura], 10; his older brother, Thomas; and their cousin, Tiffany Sackett, began pressing buttons on the gun safe’s electronic key pad and managed to open it.
The three opened and shut the door to the 575-pound safe a few times before Daniel got inside. The first time his cousin punched some numbers on the key pad and got him out, but the second time, he became trapped inside._