PORTAGE, Wis. (AP) _ Four teen-agers were arrested after a shot was fired at a school custodian who refused to hand over his car keys. The custodian was only slightly injured because the bullet was slowed by a reinforced glass door.

The teen-agers, two boys and two girls, confronted custodian Ralph Pulver at Pardeeville Elementary School late Monday, Detective Roger Brandner said.

A 15-year-old boy brandished a .22-caliber Magnum pistol and demanded Pulver's car keys, the detective testified Tuesday at a juvenile detention hearing.

Pulver refused and went back into the school, and a shot was fired at him through the door glass.

Pulver, 40, was grazed on the head and sprayed with broken glass. He was treated at a hospital and released.

The reinforced glass probably saved Pulver's life, Columbia County Sheriff Steven Rowe said.

The teen-agers were in juvenile custody pending hearings today and Thursday. The boys were ages 14 and 15. The girls, ages 15 and 17, were both runaways from a foster home, Brandner said.