Overview
- City officials concluded after a review that Monday's inadvertent activation of Denver's outdoor warning sirens was caused by human error and an improper understanding of protocol rather than a hardware or system malfunction.
- Emergency managers say a Denver Fire Department employee manually activated the sirens after receiving an unconfirmed 911 report of a tornado and in the process skipped required verification steps meant to prevent false alarms.
- The siren network functioned as designed and there was no National Weather Service tornado warning or Wireless Emergency Alert for Denver when the alarms sounded, officials confirmed.
- Denver's Outdoor Warning Siren System includes 86 sirens covering the city and the airport, and officials are reviewing who has access and how the system is used during watches and warnings.
- Officials plan a review of alerting policies, more training and exercises for staff, and added oversight after this incident and two other improper city alerts earlier this year to rebuild trust and prevent public desensitization.