I can't believe the news either. Terrible, tragic loss.
The knock-on effect is really dramatic too. My sympathies go to all the families affected by this event. There's a school in Australia who were conducting an expeiriment which was on the shuttle. The students had spent four years developing an expiriment to find out what shape spiders would weave webs in zero-G. Now, I'm not placing the spiders lives above those of the crew. But these kids had worked for so long to develop this experiment and had travelled over to the US for the launch and were probably eagerly awaiting the return of thier arachnids.