Out of all of the NASA Space Shuttles, which 2 have been destroyed in disasters?

Challenger and Columbia are the two NASA space shuttles that were destroyed in disasters. Challenger disintegrated just 73 seconds after launch on January 28, 1986, due to a failure in the O-ring seal of its right solid rocket booster, resulting in the loss of all seven crew members. Columbia, on the other hand, broke apart during re-entry on February 1, 2003, due to damage sustained from a piece of foam insulation that struck its left wing during launch, causing the shuttle to disintegrate and resulting in the loss of all seven crew members. These tragic events serve as reminders of the risks and challenges inherent in space exploration.