Failed cleanup of Gulf of Mexico
Due to an accident at BP, a lot of oil unintentionally ended up in the sea near the Gulf of Mexico. In order to ensure that this would disappear more quickly, chemicals were thrown into the water that were supposed to make the oil droplets smaller and speed up the decomposition process. Unfortunately, the chemicals had the opposite effect: the chemicals caused microorganisms to flourish and drive out the microorganisms that were breaking down the oil.
Flying has become much safer after Tenerife air disaster
The worst air disaster ever occurred on the runway of the airport on the Canary Island of Tenerife. Two Boeings collided there at full speed. One Boeing did not have take-off clearance yet, but other circumstances also played a role. It was very foggy and there was confused communication with the control tower. Since then, flying has become much safer. Airline staff are allowed to make mistakes and admit them, so that everyone can learn from them.