US endurance swimmer Diana Nyad poses before a press conference in Havana to announce her world record attempt to swim 103 miles between Cuba and Key West, Fla., without a shark cage on Aug. 7. Ms. Nyad began her journey on Aug. 7 and expects to accomplish her goal in approximately 60 hours. Franklin Reyes/AP
Diana Nyad poses for reporters before her attempt to swim to Florida from Havana on Aug. 7. The same swim was completed by Australian Susan Maroney in a shark cage in May 1997. Ms. Nyad will be protected by a surrounding electrical field and by divers who will watch for sharks and drive them away if they get too close. Desmond Boylan/Reuters
Diana Nyad speaks to media members before jumping into Cuban waters in Havana on Aug. 7. In 1979, Nyad swam from Bimini to Florida in two days, setting an unbroken distance record for nonstop swimming without a wetsuit. She has broken numerous world records, including circling Manhattan Island in 1975 in 7 hours and 57 minutes. Franklin Reyes/AP
Diana Nyad plays a trumpet before her attempt to swim to Florida from Havana on Aug. 7. Ms. Nyad was inducted into the National Women's Hall of Fame in 1986 and the International Swimming Hall of Fame in 2003. Appropriately, 'Nyad' is a variant of the Greek name Naida, which means 'water nymph.' Desmond Boylan/Reuters
Diana Nyad looks at the ocean before her attempt to swim to Florida from Havana on Aug. 7. Enrique De La Osa/Reuters
Diana Nyad jumps into the sea as she begins her attempt to swim to Florida from Havana on Aug. 7. Desmond Boylan/Reuters
Followed by Stuart Nex, a member of her team, Diana Nyad swims in Cuban waters on Aug. 7. Franklin Reyes/AP
Diana Nyad swims on her way to Florida from Havana while accompanied by two assistants in kayaks and an assistance boat on Aug. 7. Instead of swimming in a shark cage, Nyad will be protected by an electrical field and by divers who will watch for sharks and drive them away if they get too close. Desmond Boylan/Reuters
Diana Nyad swims offshore from Havana on Aug. 7. Franklin Reyes/AP
Diana Nyad makes the first part of her swim to Florida from Havana on Aug. 7. Desmond Boylan/Reuters
Video footage and eye witness accounts from the scene of a brutal murder in London on Wednesday seem to indicate that the attackers may have been politically motivated. Counterterrorism officers are leading the investigation. Two men have been arrested.
Two men with butcher knives hacked another to death Wednesday near a London military barracks and one then went on video to explain the crime — shouting political statements, gesturing with bloodied hands and waving a meat cleaver. Soon after, arriving police shot and wounded the unidentified assailants and took them into custody.