Two helicopters collided in mid-air near a popular tourist attraction in Australia's Gold Coast region on Monday, killing four people and critically injuring three more, authorities said, according to Reuters. Emergency services were called to the scene near the Sea World theme park at about 2 p.m. local time, Gary Worrell, acting inspector at the Queensland police, told a news briefing. Worrell said the two aircraft crash-landed after the collision. "As a result of that, four people have lost their lives today." The Australian Transport Safety Bureau said it had launched an investigation into the accident.