MIDDLESEX COUNTY, ONT. -- The City of London, along with several other organizations, has lowered flags to half-mast in honour of those lost in the weekend's shootings in Nova Scotia.

At least 18 people have died, includig an RCMP officer, in the mass shooting, the worst in Canadian history.

It all began when police responded to a firearms complaint in Portapique, N.S. late Saturday after numerous 911 calls, and found "several casualties."

London Mayor Ed Holder says, “This is terribly tragic and I speak on behalf of council when I express our condolences and sometimes words don't say it.”

The flags at city hall, London Police Service headquarters and RCMP headquarters, as well as all city firehalls, are being lowered.

The flags will remain lowered for three days.