Terror in Australia: A young surfer is in critical condition following a shark attack at a popular Sydney beach. Authorities have declared a mass closure of the coastline, fearing a repeat of last year's deadly tragedy. 

There have now been 4 shark attacks in NSW over the last 48 hours.

An unprecedented maritime lockdown has been declared across Sydney’s coastline after a young surfer was brutally attacked by a shark at North Steyne Beach, leaving him in critical condition.