BAYONNE, N.J. (PIX11) — Two teenage brothers drowned at a school pool in Bayonne on Wednesday night, police said Thursday.

The brothers, ages 16 and 19, were swimming at the Lincoln Community School Pool when they became distressed in the deep end around 8:30 p.m., witnesses and the three lifeguards on duty told police. One of the lifeguards spotted the two teens who appeared to be unable to resurface and entered the pool along with two other lifeguards. They were able to pull the brothers from the pool and started life-saving measures while someone called 911, according to investigators.

Officers came to the scene and assisted the lifeguards with life-saving measures. Firefighters and EMTs also followed suit. The brothers were taken to a hospital, where they were pronounced dead.

They have not officially been identified, but people who knew them spoke with PIX11 News on Thursday afternoon, as they tried to process their grief.

Isaiah Phillips was closest to the 16-year-old brother, but was friendly with both of them.

“I grew up with those two kids, and they were the sweetest kids ever,” he said. “And when I found out, I just broke out in tears.”

Phillips spoke with PIX11 News during a break from classes at Bayonne High School, where the younger of the two siblings is a student, and from which the older one graduated recently.

Bayonne’s school superintendent posted a letter Thursday revealing more details about the brothers, who are referred to as “Mr. Zheng and Mr. Jiang.”

The older sibling was home from college, according to Andres Giron, another friend of the teens.

He said that the younger brother worked after-school jobs intensely.

“His family didn’t always have much,” Giron said, “and what he was saving up for was his college, so he could go to college with his brother.”

How the tragedy happened is still under investigation, but as Jim Spiers, founder and CEO of the aquatics safety company SwimJim, pointed out in an interview, severe water emergencies often go unnoticed until it’s almost too late, or too late altogether.

“Drowning is not like a Hollywood movie,” Spiers said. “It’s a silent killer. There’s not the waving the arms, and the screaming for help. There’s water in the esophagus and they can’t speak. So, drowning is silent.”

He said that’s why water safety education is vital. Spiers is also president of the education not-for-profit Stop Drowning Now. It educates children on water safety in classrooms, as well as in pools.

He said that water emergencies are the number one cause of death in children four years old and younger.

“It’s a really big killer. It’s more than car accidents,” he said. “We need to focus on how we educate children, and get them safer around the water.”

Spiers has offered his services to the City of Bayonne. He also said that there’s a bill pending in the New Jersey legislature that would add water safety to public school curricula statewide. This tragedy at Bayonne’s indoor community pool, he pointed out sadly, may provide greater incentive for the measure to become law.

The pool is home to the Bayonne High School swim team. However, there was an open swim Wednesday night, which took place until 9 p.m.

Police said that a younger sibling was also present at the pool.

Bayonne Mayor Jimmy Davis mourned the deaths of the brothers.

“The City of Bayonne is in mourning as we learn of the passing of two teenage brothers,” Davis wrote on a Facebook post. “I ask that we all respect the privacy of the family, as they deal with this unspeakable tragedy. We all pray for comfort for our neighbors.”

The pool is closed until further notice.