All, Today's building evacuation was caused by a component failure in the air pressurization portion of the building's fire protection system. The system affected is normally filled with air in order to provide freeze protection to sections of the piping exposed to winter temperatures. When the component failed this afternoon, water was permitted to flow into the pipe triggering the evacuation alarm. At no time was the building without fire protection. Purdue's FES has completed repairs to the system and it is operating normally. As always, any evacuation alarm should be treated as real. We do not conduct tests of the Birck emergency systems without prior communication. We apologize for any inconvenience today's evacuation may have caused and appreciate your patience and understanding in this matter. Regards, Jeff Kuhn Facility Engineer Birck Nanotechnology Center Purdue University 1205 W. State St. West Lafayette, IN 47907 Ph: (765)-496-8329 Fax: (765)-496-2018