Rio de Janeiro’s happiness at winning the 2016 Olympics has been shattered with at least 12 people killed in drug-related violence. Shooting erupted as heavily-armed gang members fought police and each other. A police helicopter was brought down when the pilot was hit in the leg and lost control. He survived the crash, but two officers on board died as the aircraft exploded on impact.Police were out in force as part of an operation against traffickers in one of the city’s favela slums. The violence spread as buses and a school were set on fire. This latest explosion of gang violence comes just two weeks after Rio overcame worries about crime and poor security and won the right to host the Games. It’s thought the shooting started when one gang tried to invade another’s territory. Things worsened as police tried to impose control. Three bodies were found in a car near the entrance to the slum; it’s not clear how or when they died.