"There's a Time magazine report that says the most likely cause of the accident was an aerodynamic structural breakup. That statement shows of lack of understanding about engineering accidents," says Barry Berenberg, an aerospace structural engineer and Guide to Composites/Plastics with About.com. "The breakup was definitely caused by aero loads, but what caused the shuttle to go out of control in the first place? It could have been loss of hydraulics, burn-through from tile damage (also mentioned in the article), an electronics failure, or one of many other possibilities. Aerodynamics didn't cause the accident - something else caused the shuttle to become aerodynamically unstable."
This is like saying that someone died from heart failure. Any medical examiner will tell you that everyone dies from heart failure. The real question is 'why did the heart fail?' In the case of the Columbia, we need to know what caused the structure to break up.
Current theories focus on the heat shield on the left wing of the shuttle. Shortly after takeoff on January 16, a piece of foam insulation fell off the external fuel tank, striking the wing. Officials from NASA said they suspected the wing was damaged, but felt there was no reason for concern. The shuttle has no means of inspecting such damage, which would require a very sophisticated facility to repair and could not have been accomplished in space. Instead, they rely on several layers of redundancy. NASA cautioned that it may have had nothing to do with the accident.
Mission Controllers’ first indication of trouble Saturday was the loss of temperature sensors in the left wing's hydraulic system. Columbia had just re-entered the atmosphere and had reached the point at which it was subjected to the highest temperatures, up to 3000 degrees Fahrenheit.
NASA has appointed an independent commission to investigate the disaster.
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Conclusion
President Bush, in his speech concerning the tragedy said, “In the skies today we saw destruction and tragedy. Yet farther than we can see there is comfort and hope. All Americans today are thinking, as well, of the families of these men and women who have been given this sudden shock and grief. You're not alone. Our entire nation grieves with you. And those you loved will always have the respect and gratitude of this country. The cause in which they died will continue. Mankind is led into the darkness beyond our world by the inspiration of discovery and the longing to understand. Our journey into space will go on.”We will push through this tragedy, as we have through far too many others and emerge stronger and with more resolve.