Why shuttle space Columbia exploded while re-entry to the base?

The Space Shuttle Columbia exploded during re-entry on February 1, 2003, due to damage sustained during launch. A piece of foam insulation broke off from the external fuel tank and struck the left wing, compromising the thermal protection system. As the shuttle re-entered the Earth's atmosphere, superheated gases penetrated the damaged wing, leading to structural failure and ultimately the catastrophic breakup of the shuttle. All seven crew members aboard were lost in this tragic accident.