A Dartmouth College swimmer died after trying to swim four laps underwater without breathing while on vacation in Florida. Tate Ramsden, 21, had gone to the YMCA Selby Aquatic Center to swim laps. Ramsden swam around 4,000 yards — over two and a quarter miles — before attempting an underwater swimming technique called a “100,” which is four laps across the pool without coming up for air. During this routine, his sister and cousin noticed a “lack of movement” by Ramsden and he was pulled from the water. He was given CPR and paramedics were called, but attempts to resuscitate him were unsuccessful and the 21-year-old was declared dead at the scene.