Melbourne, Jan 25 : A 43-year-old Indian national and three of her relatives, all in their 20s, died on Phillip Island in one of the worst drowning tragedies in the Australian state of Victoria since 2005, local media reports said. Off-duty lifeguards surfing at the unpatrolled Forrest Caves beach were the first to rush to the aid of the struggling group on Wednesday at around 3.30 pm, The Age reported. They found three women and a man unresponsive after being pulled from the water and were given immediate CPR by the emergency services who had rushed to the site. Three of the victims were pronounced dead at the scene, while a woman was airlifted to The Alfred Hospital in Melbourne in critical condition where she succumbed to her injuries. Victoria Police Eastern Region Assistant Commissioner Karen Nyholm told The Age that they were from Clyde in Melbourne's south-eastern suburbs and that the 43-year-old was an international visitor. The Indian High Commission condoled the deaths as a "heartbreaking tragedy" and assured all assistance to the family and friends of the deceased. "Heartbreaking tragedy in Australia: 4 Indians lost their lives in a drowning incident at Phillip Island, Victoria. Deepest condolences to families of the victims. @cgimelbourne team is in touch with friends of the deceased for all necessary assistance," the Indian High Commission said in a social media post on X on Thursday. "We all worked tirelessly to help those people," Ambulance Victoria manager Paul James told The Age. Victoria Police said investigation is on as to what led to the tragedy even as emergency services warned against swimming at the relatively remote Forrest Caves beach -- a spot best suited to surfers. "I couldn't define the worst ever, but I certainly say this was horrific," Nyholm told The Age. Liam Krige, Life Saving Victoria's general manager of operations, said at a press conference that 19 people had drowned in Victoria since December 1 -- two more than the same period last summer. "Behind each one of these drownings, there is a family; there's a brother, there's a sister, there's a mother, there's a daughter," he said. /IANS