Lunenburg Police Department K-9 Jerry was used to track down a group of children who became trapped inside an underground bunker near Mirror Lake at Devens on Friday night.

DEVENS — A group of teenagers who became trapped inside an underground bunker in the woods near Mirror Lake were rescued by first responders on Friday night, authorities say.

The four teens, ages 16 to 17, entered the bunker while exploring the area and became locked inside the structure when the wind blew the door shut, according to a post on the Lunenburg Police Department Facebook page.

The teens were able to reach their arm far enough out a bunker air vent to get cellphone reception and call for help.

The Lunenburg Police Department’s K-9 Jerry was dispatched to the area, along with the Massachusetts State Police, the Department of Defense Police and the Ayer Police Department. Although the children were unsure exactly where they were in the woods, dispatchers at Nashoba Valley Regional Emergency Dispatch were able to get enough information to narrow down the search area.

Jerry was deployed near the kids’ vehicle and tracked across the street, alongside the road, through the woods and to the buried bunker approximately a half mile from the starting point, police said.

Officers from each agency helped to force the door open, freeing the children from the bunker.

The teenagers were inside the bunker for approximately an hour and a half, according to police.

“Thankfully they were unhurt, found quickly and sent home safe,” the police Facebook page states. “This positive outcome resulted from good communication, coordination and teamwork on behalf of all involved.”

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