Livonia tornado: Why sirens didn't alert Detroit suburb

(FOX 2) - The blast of severe weather that smashed into Southeast Michigan late Wednesday afternoon started as quickly as it ended. Left in its wake was downed trees, power outages, collapsed buildings, and one death.

The National Weather Service has confirmed it was a tornado that brought much of the carnage to Livonia, including bringing down a massive tree that crashed through a home, killing a toddler. It was rated as an EF-1, which is considered a weak tornado that brings wind speeds up to 110 mph.

Yet, no tornado siren went off warning residents of the incoming danger. Why?

While there were severe weather conditions that moved through on June 5, they included ingredients that don't normally form into a tornado. FOX 2's Derek Kevra explained on social media the storm system that arrived was a "squall line with a bow echo."

That's a line of thunderstorms that appear in a crescent shape on the radar. 

They usually bring gusty winds, but nothing powerful enough to bring a tornado. But in circumstances where they do form, they'll do so quickly before dissipating shortly after. That can make them hard to see for forecasters at NWS - and until the weather service issues a tornado warning, the county's emergency management won't issue an alert.

The blaring sirens that ring throughout an area in the path of a potential tornado is often the best way to alert people so they have time to get to safety. 

Just in Oakland County, there are over 270 sirens that can be heard a mile away. Kevra got a tutorial on the work that emergency managers do last year.