From the City of London:
As part of Emergency Preparedness Week activities, the City of London will be testing its Alert London Notification system on Wednesday, May 9 at 10:55 a.m.
At that time, anyone who has a publicly registered residential or business phone number as well as residents who have signed up to receive notifications from this alert system will receive a test message based on their registered preference (email, text). This will allow the City to evaluate the system and help ensure that it will reach London residents in the event of an emergency.
Residents can sign for Alert London Notifications. London.ca/alertlondon
Individuals who receive the test message should not call 911 – this is only a test.