A second period swim class made the discovery. Aurora Campoy's 14-year old son was among the witnesses.
"From what he told me yes. So he got to see. They were pulling the covers off of the pool," Campoy says.
There had been a tarp on the pool at Piedmont Hills High. And school officials say the surrounding gate had been locked tight after swim practice yesterday evening.
"All of our pools are secured. They have an extra high fence. They have barbed wire around it. All the doors from the inside are locked. So you have to be intentional to get into the pool," says Chris Funk, Superintendent of the East Side Union High School District.
Authorities now believe the man may have entered through a breach in the fence. They say the body was discovered fully clothed and weighed down with some sort of weights.
"We were able to utilize our special equipment to retrieve the body, to pull the body up out of the pool. That body is now in the custody of the Santa Clara County Coroner's Office." says Capt. Christopher Salcido with the San Jose Fire Department.
Officials at Piedmont Hills do not believe the person was a student. And they say all staff members have been accounted for.
First responders said the person was not carrying any identification.
The school brought in counselors for anyone who needed them, but then decided to release students early.
"We're informing our students about why we're releasing them and to be respectful of the situation and to allow them to have counseling if they need counseling," says Funk.
Still many parents were distraught by the news.
"I'm just feeling really terrible. My son is doing swimming right now and it's just scary," says Maria Redet, a parent.
As it turns out, her son's swim class would have been later in the day, so he never made it to the pool. Still he's not sure he wants to dive back in any time soon.
"I don't think I'm probably going to go swimming in that pool ever again," says freshman Ambroise Redet.
School officials say more counselors will be available Monday. A scheduled school spirit event Friday night has been postponed.