Four Cars, Semi Crash During Snowfall

Two people had to be extricated from their vehicles after a crash involving four cars and a tractor trailer during the season's first big snowfall.

A total of five people were injured -- one critically -- in the midday crash near Half Day Road on the Tri-State Tollway in Deerfield, said Ian Kazian, the fire chief of the Deerfield-Bannockburn Fire Department.

Kazian said he believed the crash was weather-related, and offered advice to those taking to the roads: slow down, keep the distance between you and the vehicle in front of you, and if you can, stay off the roads."

While the evening rush was worse than the morning commute, for most it appeared to be just a minor hindrance. Salt placed down on the roads seemed to be doing its job melting the snow and keeping the roadways from freezing over.

There were a couple of fender benders along Lake Shore Drive, but nothing major, officials reported.

NBC Chicago crews traveling along the Dan Ryan and Eisenhower expressways reported better-than-expected conditions, though still slow-going, for the season's first big snow.

By evening, the full fleet of Streets and Sanitation's snow-fighting equipment was out in force. Those crews can be tracked online via the city's new "plow tracker" website.

Commissioner Tom Byrne, watching weather reports, said he anticipated a "great" rush hour for Friday morning.

The news wasn't so positive at the city's airports, which proactively canceled flights as the snow approached.

At Midway, Southwest Airlines canceled all flights in and out of the facility between 1 p.m. and 6 p.m., affecting about 100 flights. Other airlines at Midway canceled more than 40 more flights for the day.

At O’Hare, airlines canceled more than 420 inbound and outbound flights and reported delays because of de-icing procedures. At its peak, O'Hare was reporting delays as long as 1 hour and 20 minutes.

As always, travelers were advised to check their airlines’ Web sites to confirm the status of their flights.

Flurries moved into Chicago around 9:30 a.m. after a winter storm advisory went into effect. Just before 11 a.m., the advisory was upgraded to a winter storm warning.

To prepare, the Illinois Department of Transportation readied 465 snow-fighting trucks Thursday morning. Still, the Chicago area hasn't dealt with this much snow in months, and IDOT warned commuters to stay alert and leave extra time to prevent crashes and slide-offs.

For traffic and snow updates, follow @Matt_Rodewald, @nbcchicago and @nbcchicagowx on Twitter.

[View the story "Jan. 12, 2012 Winter Storm" on Storify]

<a href="http://

News breaks at inconvenient times. Take NBCChicago.com with you on your iPhone app and be in the know whereever you go. Visit the app store and download it today!