text:  Officials stressing shark attacks are rare, but saying that the risk can be reduced by swimming in groups near a lifeguard and avoiding swimming near piers. Tough news for the Team USA Gymnastics team. Three frontrunners to join Simone Biles and Paris have suffered injuries at the U.S. Olympic trials. Kayla DiCello carried off. The mat had an awkward landing on the vault. Shalise Jones seeming to hurt her knee during warm-up on the vault. And Skye Blakely pulling out of the trials on Thursday after an Achilles injury.