Manchester (Conn.) High School's pool has been shut down and its physical education swimming unit removed indefinitely, following the Nov. 21 drowning of a freshman boy.

New information revealed Monday indicates that Malvrick Donkor, a Ghana native who recently moved to the Manchester area, was underwater in the deep end of the pool for approximately 17 minutes. According to the Hartford Courant, a surveillance camera at the pool showed the 14-year-old student climbing down a ladder into the pool's deep end. "There's no splashing, no flailing like you would typically think of," an unnamed source who viewed the surveillance footage told the newspaper. "He just slipped underwater. Other kids were swimming over the top of him, not knowing he was down below."

It wasn't until after class ended that students noticed Donkor's body. P.E. teacher Thayer Redman jumped in and pulled the boy out of the pool; he later died at a local hospital. Redman has been placed on administrative leave, and school officials aren't talking.

Manchester High's principal Matthew Geary did, however, post a letter to students' parents and guardians on the school's home page, inviting them to a vigil Monday night and assuring them that an investigation has begun. "While many questions remain about this terrible tragedy, we have very little information to share at this time. An investigation is under way and will be done thoroughly by trained professionals. The Manchester High School pool is closed until further notice and the swimming unit has been removed from the Physical Education curriculum indefinitely."

According to local media reports, Donkor is the second area high school student to drown in a swimming pool during a supervised P.E. class in 2012. Marcum Asiamah, 15, died Jan. 11 after being found in the East Hartford High School pool.

In October, the family of 14-year-old Antonio Reyes, who was found at the bottom of the deep end of the Wenatchee (Wash.) High School swimming pool after a P.E. class in late 2011, reached a $2 million settlement in a negligence lawsuit filed against the Wenatchee School District. The settlement also called for reforms, including that the district have a certified lifeguard on duty when people are in the pool and that greater efforts be made to evaluate the ability of students to swim, the Associated Press reports.