Why Were Tornado Sirens Activated?

Last night, when the damaging winds got to Detroit (knocking out power to 140,000 hems and businesses) the tornado sirens were sounded during the night. Why?

Turns out that a number of the communities have "70 mph winds" as an activation criterion. Those who have read When the Sirens Were Silent know there are real issues involving communication and false alarms when the sirens are used for anything except tornadoes. Please consider this if you are involved with siren activation policy.