Five curious boys had to be rescued from a Staten Island sewer system on Tuesday after they crawled into a tunnel, went deep inside, and got lost, according to the New York City Fire Department (FDNY).

Chief of Department John Hodgens reported that the FDNY received an emergency call around 6 p.m. on Tuesday about children trapped in the sewers. Firefighters found the kids' backpacks at the tunnel entrance under Clove Lakes Park.

Lt. John Drew said the tunnel had a 40-inch opening that later narrowed to 30 inches, making it hard to navigate. A firefighter crawled through the tight space with a rope and breathing equipment to rescue the boys.

Firefighter John Loennecker said the kids were relieved to be out of the cold, wet tunnel. "They crawled for an hour in the dark, with only one cell phone light," he said.

All five kids were taken to Richmond Medical Center for evaluation. One firefighter suffered minor injuries during the rescue.