CHICAGO (WLS) -- Drivers could see dangerous conditions on the roads as overnight snowfall blanketed the Chicago area. Some schools in the Chicago area and Northwest Indiana announced school closures and delayed starts because of the weather.

St. Louis City Hall called tornado siren repairs an emergency this past spring. So why are those repairs still in limbo? FOX 2 News reported on the failing sirens earlier this week and returned to city hall to find out the hold up.

Tornadoes ripped through portions of the South overnight, triggering widespread damage, coupled with fears of flooding.

America has faced devastating tornadoes throughout its history. The Tri-State Tornado of 1925 remains the deadliest. Many of these catastrophic storms struck before advanced warning systems existed. This led to significant loss of life and destruction.

Here are more pictures from the November 6 tornado. Unfortunately, tornadoes are a recurring aspect of life in the US. Here are 15 facts about these formidable and enigmatic weather phenomena.