The Greek diaspora in Australia is mourning the death of Mercury Psillakis, who was killed in a shark attack in Sydney. According to the Greek-Australian, Melbourne-based news outlet, Neos Kosmos, the 57-year-old Psillakis leaves behind his wife, young daughter, and twin brother.

The experienced surfer sustained fatal injuries after being attacked on Dee Why beach on Saturday morning (local time) while surfing with friends about 100 meters from shore.

Authorities have not yet clarified what species of shark was responsible. Several beaches were closed to the public today as a precaution.

Other surfers pulled him from the water, but he had lost a significant amount of blood and died on the spot, according to Police Inspector Stuart Thomson.

Inspector John Duncan described the incident as a major tragedy: “It’s something horrible, truly horrible. These are the kind of dreadful incidents that happen very, very rarely… With tomorrow being Father’s Day, the tragedy is even more painful,” he said.

An eyewitness told Sky News that the shark was “one of the biggest he had ever seen,” estimating its length at about six meters. “There was a man in the water shouting, ‘I don’t want you to bite me, don’t bite me, don’t bite me,’ and I saw the shark’s fin coming out of the water—it was enormous,” he said.