What initial event compromised the Space Shuttle Columbia's thermal protection system?
Answer
A piece of insulating foam struck the leading edge of the left wing during launch.
The disaster was traced back to a piece of insulating foam that broke off during launch and impacted the thermal protection system located on the leading edge of the left wing.

#Videos
What Happened To The Bodies Of The Columbia Crew? - YouTube
What Happened to the Bodies of the Columbia Disaster Crew
Related Questions
What initial event compromised the Space Shuttle Columbia's thermal protection system?What was the approximate speed (Mach number) when the shuttle wing structure failed?Which three states were covered by the search field for the shuttle debris?What was the key forensic technique used to definitively identify the astronauts?How is the physical fate of the crew described in relation to the vehicle's structural failure?What did the location and type of recovered debris provide clues about?What dichotomy was noted regarding the endurance of the hardware versus the biological payload?What description was given for the forces experienced by the crew inside the cockpit during breakup?What specific personal items were recovered that offered poignant reminders of the individuals aboard?What ultimately allowed NASA and the military to return remains to the families for private burials?What was the primary component of the search effort involving specialized recovery teams?