SYDNEY - Police in Australia say two young children are fortunate to be alive, after they were thrown clear and survived a theme park ride accident that killed four adults, including their mothers. Two men and two women died Tuesday at Dreamworld, on a ride called the Thunder River Rapids. A police official in Queensland state says closed-circuit TV shows the ride was coming to an end when two rafts collided. One flipped backward and tossed some of the victims into a conveyer belt.