It happened around 8:30 p.m. at the Lincoln Community School, during community swim hours, and police say three lifeguards were on duty at the time.
The victims, ages 16 and 19, have not been identified, but the younger was a junior at Bayonne High School and the older a recent graduate.
Grief counselors were on hand at the school Thursday for anyone who may need help.
"It shouldn't happen," neighbor Luann Beatrice said. "It's not like they were 2 and 3. They were 16 and 19, right? They swam, and there's supposed to be a lifeguard."
Many are trying to make sense of the tragedy.
"To lose one son would be a horrific tragedy, but two at the same time and no explanation?" Beatrice said. "It's sad."
Bayonne police said that according to witnesses and the three lifeguards on duty, the two victims were observed to be in distress in the deep end of the pool.
As a lifeguard approached the deep end, he observed the two victims unable to resurface and entered the pool with the other two lifeguards.
They were able to remove both victims from the pool and immediately began life-saving measures as the 911 call was placed.
First responders arriving shortly after 8:30 but were unable to revive the brothers.
They were taken to Bayonne Medical Center, where they were pronounced dead after further life-saving efforts were unsuccessful.
"Our hearts and prayers go out to the family and to all of our community," Bayonne Superintendent John Niesz said.
Mayor Jimmy Davis says the victims' family is asking for privacy.
The pool, located in the primary school, is open to the public at night. It is closed as the investigation continues.
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