A Fire Drill in Toronto, Canada not only created panic, but it brought with it unwanted publicity.

CNN reports that Police in Toronto, Ontario, received a call at 10:47 a.m. reporting
that several armed men had entered the Bickford Centre, an adult
education center where adult literacy training and other courses are
held.Officers responded to the building and blocked off traffic on surrounding streets and the center itself.

On the scene, police soon discovered that the
“threat” was nothing more than a training exercise; the reported
suspects had simply been participating in a safety drill.

“School officials were conducting a drill but did not inform anyone else,” Vella said…..

http://edition.cnn.com/2009/WORLD/americas/05/21/ontario.false.alarm/index.html?eref=edition

Lesson: In any Crisis simulation(of which Emergency Response plays a small part), it is vital to determine various stakeholders communication needs and the communication protocols to be followed during such a crisis.

In this case, good intentions, but lack of planning sank the ship.