The Columbia disaster occurred on Feb. 1, 2003 when the space shuttle broke apart, killing its entire crew. An investigation led to changes in NASA procedures.
Columbia Disaster: What happened, what NASA learned
Columbia disaster, History & Crew
Space shuttle Columbia disaster: 20 years later, East Texas looks back at its place in national tragedy, Local News
Columbia was the only space shuttle orbiter to have black tiles on the upper surfaces of the wings. Challenger was a test vehicle that was then converted to a space rated vehicle.
How Groupthink Contributed to the NASA Columbia Disaster – Science of Education Blog
Lyle James (DOZA) Doza (1936-2016)
Space Shuttle Columbia disaster - Wikipedia
NASA marks 20 years since space shuttle Columbia disaster
Organization at the Limit: Lessons from the Columbia Disaster
NASA marks 20 years since space shuttle Columbia disaster - ABC News