By Lauren Leamanczyk, WBZ-TV

WESTFORD (CBS) – A Westford teenager is recovering from serious injuries after a “pool hopping” accident.

18-year-old Kelsey Gallagher and a friend tried to go for a swim in Chester Cook’s pool around 12:30 a.m. Monday. The problem is Cook’s pool is empty for repairs.

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Empty pool a Westford teen accidentally jumped into.

A Westford teen accidentally jumped into this empty pool.

Cook was asleep in bed when it happened, and woke up to pounding on the door. It was Kelsey’s friend begging him for help. He woke up and called 911 and then went to check on the teenager.

“Seeing someone at the bottom of the pool like that. That time of night. It was dark, didn’t really know what was going on. Yeah, I was really afraid she was seriously hurt,” he told WBZ-TV.

According to Jill Gallagher, Kelsey’s mother, she suffered a fractured skull, a broken wrist and a spinal injury. She is in stable condition and will recover. Jane Gallagher says her daughter woke up apologizing and asking about her friend.

Cook doesn’t know either of the women and doesn’t know why they chose his pool.

“I asked, I said why did you pick on me and the girl said, well we were just riding by and we were just looking for a place to get cool,” Cook said.

His pool is primarily hidden from view. A six foot privacy fence blocks the view from the street and the rest of the area is surrounded by a four foot tall chain link fence.

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In fact, Cook is the town of Westford’s building inspector. It is his job to make sure pools are up to code.

“I have everything that makes the pool legal, probably a few more and we’re careful with it too,” he said.

Westford Police said Wednesday Gallagher and her friend Alexis Mcauliffe, 20, will be summonsed to court for trespassing.

Cook posted on his Facebook page how grateful he is to emergency responders who arrived quickly to help Kelsey. He believes their fast work may have saved her life.

He hopes this ill-advised jump highlights the need for pool users and owners to make safety a priority.

“Thank god the girl’s still alive and I hope she’s well,” he said.

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Kelsey is a senior at Wesford Academy. Her mother says she hopes she is released from the hospital in time to graduate Friday.