"The myth of panic" in the media
An interview on Australian radio.
There's a blog devoted to the idea and the article, on Metafilter.
The piece was reproduced in the French magazine, Sciences Humaines.
San Fransisco Chronicle: Sirens Key to East Bay Alert System
Health Scout: Sept. 11 Brought out Best in Crowds
United Press International: Altruism, not panic, prevails in disasters
Chicago Sun-Times: Media ignored calm amid the 9/11 chaos
Los Angeles Times: When situations heat up, most of us keep our cool
ScienceDaily Magazine: In Disasters Panic is Rare; Altruism Dominates
The Bergen Record: Orange Terror Alert Brings Extra Police Presence