Quake calls jammed cell phone networks
http://www.sfgate.com/cgi-bin/article.cgi?f=/c/a/2007/11/01/BAK6T4681.DTL
"In the first real-world disaster test of local cellular networks, thousands of mobile phone users were unable to connect calls in the hour following the 5.6 earthquake that struck the Bay Area shortly after 8 p.m. Tuesday."