Frozen and shrunk 0 rings that provided the seal between fuel areas— result— fuel blew by the O ring and burn it away with red- hot jet of oxidizer/fuel causing explosion of the large tank. They never had a chance. Eerily, the crew capsule fell on it’s own to the water at high speed to break apart— the astronauts inside were already dead (that is- it is hoped they were). A helmet with part of Onizuka’s skull inside was found on sea floor, from breakup of the crew capsule. A terrible loss of great people. Saw it happen from 25 miles to the West, and will never forget it.
“the astronauts inside were already dead (that is- it is hoped they were).”
Astronaut Dr. Story Musgrave says the evidence shows they were still alive until the crew cabin impacted the sea.
Astronauts Likely Survived Challenger Explosion
https://www.youtube.com/watch?v=uqcd_3daPQ8
Actually there was no explosion. The SRB leak burned through an aft SRB support arm. That allowed the SRB to pivot on the forward support, crushing the intertank area. The whole thing was an aerodynamic breakup with a rapid burn of dispersed propellants. Its just easier to say ‘exploded’ rather than go through this explanation every time.
I met Onizuka once. I was at the Michoud facility in New Orleans on other business when he came through on NASA business. Very nice guy. Always sad to hear of the death of someone you've actually met.