An Australian man was celebrating a friend’s 30th birthday at the Mary River Wilderness Retreat, a popular tourist destination in Darwin, Australia on Saturday, when he was attacked by a crocodile after he and a friend swam across the river.

Sean Cole, 26, was celebrating with 15 friends when he and a friend decided to swim across the river despite multiple staff warnings not to get close to the water due to the high crocodile population.

According to the Associated Press, they made it across the river and were swimming back around 4 p.m. when a 16-foot crocodile snatched Cole between it’s jaws and dragged him below the water.

Police and a crocodile management team arrived at the scene to search for Cole but have not found any trace of him. An officer shot one of the largest crocodiles in the water, but they are still unsure if that is the crocodile that attacked Cole.

Besides numerous signs set up around the water, the staff also warned the partygoers not to get to close to the river because it holds the greatest population of adult saltwater crocodiles in the world, Examiner reports.