On 20 April 2010, while drilling at the Macondo Prospect, an uncontrollable blowout caused an explosion on the rig that killed 11 crewmen and ignited a fireball visible from 40 miles (64 km) away. The fire was inextinguishable and, two days later, on 22 April, the Horizon sank, leaving the well gushing at the seabed and causing the largest oil spill in U.S. waters.
4.9 km (3 miles) in two days.
