CAPE TOWN, South Africa — Three South African navy personnel died and a senior officer was in critical condition after seven crew members of a submarine were swept off its deck by big waves as a helicopter attempted a "vertical transfer" of supplies, the Department of Defence said Thursday. Wednesday's accident happened as an Air Force Lynx helicopter was attempting what's known as a “vertrep” — or vertical replenishment — of supplies to the SAS Manthatisi submarine on the ocean surface off the coast of Cape Town, the department said. The operation was immediately called off and a rescue effort...