 Tonight, patrols on the water and in the air along South Padre Island, Texas. After this terrifying scene, a shark seen thrashing in shallow water, authorities believe it's the same shark that bit two swimmers, including Rainer Cardina's son-in-law. He jumped up out of the water saying, shark, shark, shark. And that's when adrenaline kicked in. I went right after him. Rescuers dragging Tabitha Sullivan out of the water.