© GETTY IMAGESIt is believed a tiger shark like this one attacked the teenager.
Jose Ernesto da Silva had his penis ripped off by a shark as he swam with pals over the weekend, according to reports.
Shocked onlookers rushed into the water to assist the terrified young man and pulled him from the ocean.
He died in hospital Monday.
The 18-year-old had been instructed by lifeguards to come closer to shore prior to the attack, Brazilian media reported. Signs warned that deeper water could result in an attack.
"At the exact moment in which the lifeguards asked for them to come closer to the beach, he was bitten," a fire official said.
The incident occurred on Piedade beach near Recife on the central coast.
Rescuers tried to stem the gushing blood with tourniquets. In a graphic video posted online, the crowd urges da Silva to breath.
© FocusOn NewsA teen has died after he had his penis and leg torn off in a horrific shark attack off a Brazilian beach
Experts believe the predator was likely a tiger shark.
"He would go in secret, because he knew that I thought it was dangerous. I wasn't worried because I thought he was somewhere around the house," his mother, Elisangela dos Anjos, told JC Online.
"When I heard about it I went crazy, all the neighbours heard me screaming."
The stretch of coast is notorious for shark attacks where 80% of the country's incidents are recorded.
On April 15, Pablo de Melo, 35, had to have a leg and a hand amputated after being attacked by a shark at nearly the same spot.
It takes a special kind of loser to take a cellphone video of a guy who had his junk lopped off by a shark...