SPIRIT LAKE - A.J. Marksworth was pleasant to be around and enjoyed life to the fullest, acquaintances say.

The Spirit Lake 16-year-old died on Friday morning at Sacred Heart Medical Center in Spokane after he was involved in an accident on Spirit Lake on Wednesday afternoon.

"He was a kind kid who loved living life," said Chris McKenzie, a family friend. "He was always on the move to do something fun. It's a tragedy when something like this happens so close to home."

According to the Kootenai County Sheriff's Department, Marksworth and Nathan T. Thiers, 15, Spirit Lake, were wading across the mill pond area at the north end of the lake when Marksworth, who didn't know how to tread water, slipped into an area that's about 8 feet deep.

Thiers tried to pull Marksworth to shallower water, but the two became tired and were separated. Marksworth then sank to the bottom for 10 to 15 minutes before Kootenai County deputy Bob Bjelland arrived on the lake in a private boat and pulled the teen out.

Thiers was treated and released from Kootenai Medical Center on Wednesday night, while Marksworth was airlifted to Sacred Heart via a MedStar helicopter.

Marksworth played football at Timberlake High.

"He worked hard at football and he'd stick around and help me paint the field," said Tim Cronnelly, Timberlake's athletic director. "He was a nice kid and he had a great way about him. Nothing seemed to bother him."

Joey James, a counselor at the school, described Marksworth as a happy and polite student who had a lot of friends.

"He was a happy-go-lucky kid," James said.

The Memorial for A.J. Marksworth account has been set up at all area Inland Northwest Bank branches to assist his family.

Marksworth is the third Timberlake student to die in the past four months.

"We're hoping this small town sticks together during this tragic time," said Roxanne Kusler, branch manager for INB in Spirit Lake.