Two teenage brothers drowned in a swimming pool at a New Jersey school that was being monitored by at least three lifeguards, authorities said.

The siblings, identified only as “Mr. Zheng and Mr. Jiang,” were in the deep end of the pool at Lincoln Community School in Bayonne on Wednesday when lifeguards noticed they were in distress and unable to resurface shortly before 8:30 p.m., Bayonne Police said.

Three guards jumped into the water and pulled the brothers out and administered CPR immediately, authorities said. They also called 911 and arriving paramedics arrived in minutes to aid in life-saving attempts.

The boys were then rushed to Bayonne Medical Center, but couldn’t be saved, police said.

The 16-year-old was a current Bayonne High School junior, while his 19-year-old brother had recently graduated from the school, according to Bayonne Public Schools Superintendent John Niesz.

“Our hearts and prayers go out to the family and to all our community,” Niesz said in a statement. “We will have additional crisis counselors and guidance counselors [Thursday] at all schools.”

The Bayonne Police Department, the Bayonne School District, the school insurance provider and OSHA are each conducting independent investigations into the drowning.

The Bayonne School District is also organizing a fundraiser on behalf of the boys’ family. The district is collecting gift card donations at Korpi Ice Rink over the weekend.