There were several explosions. The integrity of the heat shield tiles was breached, and heat/fire from the high kinetic energy of the shuttle in its high spot in the gravity well was not able to dissipate in external heat and light against the friction of the upper atmosphere. 3000 degree heat, greater than lava or the surface of the sun, penetrated into the left wing and melted the frame and caused instability. The nitrogen in the left tire may have been the first explosion. The heat penetrated further and hit the propellant fuel tanks for the retrorockets and they exploded.
This is physics. Like the failure of the tail section, held on by plastic composite bolts, of the American Airlines plane in New York in 2001 after 9/11 was physics.
Physics, not the hand of God, nor of a terrorist, IMO.
We were given free will. We can mess around with stuff and get ourselves into trouble. Physics are the boundaries of our playpen.
God rarely suspends the laws of physics for our benefit so that we do not suffer the consequences of our actions. I doubt that he suspends them to our detriment.
When you do risky things, when you have fallible humans putting complicated machines together, then bad things can happen as people and their understanding of their work is not perfect. The prior deaths of astronauts were not messages from God, they were accidents of a child taking their first steps in a new field of endeavor.
Coincidence is a tempting explanation. But I think that President Bush actually explained the bunching of "coincidences" better in the State of the Union speech.
"This country has many challenges. We will not deny, we will not ignore, we will not pass along our problems to other Congresses, to other presidents, and other generations."
Too many things have not been attended to on the watch of the last President, and a lot of chickens are coming home to roost.
NASA has been underfunded and ignored, and not given a new vision and inspiration. Under Reagan we built the B1 and B2 stealth fighters and bombers to replace our aging B-52 bombers, a huge leap in technology. Our current fleet of shuttles was designed over a generation ago. We can still get reasonable use out of our remaining fleet, down 40% in strength since Challenger and now Columbia have been destroyed. But we need to design a more modern space transportation system with some forward leaps in technology and safety that may be already developed or could be with some dedication and funding.
But we do need perspective. So far we've lost less people than Columbus lost coming to the New World. He lost the Santa Maria, his flag ship, the best of his three ships. It sank near San Salvador, and he had to abandon crew, all of whom died before he returned on his second vogage.
God said Abraham's seed, descendents, would eventually count more than the stars of the skies. I believe that will not be possible till man has spread to the stars. When Christ said "And other sheep I have, which are not of this fold: them also must I bring, and they shall hear my voice; and there shall be one fold, and one shepherd," I believe he was speaking of personally going to another world to save the sentient souls there, although the Mormons may disagree and cite their Book of Mormon and the ministry of Christ in the Americas.
Conjecture is fun and I can be just as far out as you, Quix. :-)