WINSLOW, Maine (AP)   An 8-year-old boy has been seriously injured in a fall from a zip line at a Maine summer camp.

Police say the New York City boy lost his grip while riding the zip line at Camp Caribou in Winslow around 5:15 p.m. Tuesday.

The boy struck his head on a metal rowboat during the fall, and he has been hospitalized in serious condition.

Maine State Police spokesman Steve McCausland says the boy was among several others who used the zip line to enter a pond from a sloping height of 50 feet (15 meters).

Use of the zip line has been suspended pending the outcome of an investigation.

Camp officials have not responded to a call for comment.