A 6-year-old Herriman boy is in critical condition after an accidental fall from a second-story window onto a concrete driveway Thursday evening.

Salt Lake County sheriff's dispatch supervisor Adam Almond said the Unified Fire Authority received a call shortly before 4:30 p.m. to a residence near 5500 West and 14500 South.

The boy had been playing with friends in a second-floor bedroom, jumping from a window sill to an air mattress on the floor of the bedroom. The boy apparently leaned or lost his balance into a screen in the window, which popped out of its frame, and he fell to the driveway, about 16 feet below.

A medical helicopter responded, and the boy was airlifted to Primary Children's Medical Center with serious head injuries.

The boy remained in critical condition late Thursday.