Columbia Disaster
In 2003, the space shuttle Columbia was heading back to Earth when a piece of foam detached from the shuttle’s external tank and breached its wing. This caused the vessel to explode when it attempted to re-enter the atmosphere. All seven astronauts aboard Columbia were lost.
Oddly enough, a similar issue had occurred when the Columbia had taken off 16 days earlier but no action was taken to correct the flaw that could have prevented the loss of all hands aboard the ship, not to mention $13 billion.