The Union of Concerned Scientists [2]' David Wright [3]explains why a grapefruit-sized piece of debris caused NASA to evacuate the International Space Station. Listen [4].
Links
[1] https://ploughshares.org/file/335
[2] http://www.ucsusa.org
[3] http://ploughshares.org/expert/143
[4] http://www.kcbs.com/topic/play_window.php?audioType=Episode&audioId=3567097
[5] http://www.kcbs.com/World-News/9001