DELLWOOD, Mo. (KMOX) -  Two teens find a gun, start playing with it — and it goes off.

Now one of them is in the hospital and the other’s facing charges.

St. Louis County police spokesperson Randy Vaughn says it happened early Wednesday morning when a pair of 16-year-olds discovered a loaded revolver behind a gas station on Halls Ferry Road near Woodwind.

“They took the revolver back home to one of their residences and allegedly began playing with the gun,” Vaughn said. “They were pointing it at one another when one of them pulled the trigger and shot the other one in the right arm.”

Vaughn added that the boys’ first mistake was touching the gun once they found it behind a BP station.

“Anybody that finds a weapon that does not belong to them needs to contact their local police department,” Vaughn explained. “What we do is take the weapon and fire it inside our facilities in a safe place and determine if it’s ever been used in a crime.”

The shooting victim’s expected to recover.

The teen who pulled the trigger was taken to family court where he faces a count of 2nd-Degree assault.