It’s one of the deadliest holidays for driving, but this year, a post-Thanksgiving winter storm made travel conditions a nightmare for many drivers. The storm impacted states in the Midwest, including Kansas, Nebraska, Missouri, Iowa and Illionois.

More than 7,600 flights were delayed on Monday, and 1,593 were cancelled due to the weather. Winter storm warnings were still in effect in parts of Chicago on Monday morning, which caused delays at O’Hare International Airport.

Nearly 19,000 flights were cancelled on Sunday, and more than 300,000 homes in the Chicago area lost power due to the storm.

Kansas Governor Jeff Colyer declared a State of Disaster Emergency.

“We urge you to change your travel plans and stay off the roads,” said the Kansas Division of Emergency Management on Twitter. “If you have to travel make sure you have a full tank of gas when you leave. There are power outages along some major highways with an extended line of no available gas due to the outages.”

The stormy weather also spelled bad news for drivers, as inclement weather made driving more hazardous. The storm caused accidents across the Midwest as drivers attempted to make their way home after the Thanksgiving holiday.

Thanksgiving is already a dangerous holiday for drivers, as thousands of people end up in emergency rooms due to injuries each year. With more people on the road – and many driving while intoxicated – the risk of getting into an accident is much higher than average.

In Missouri alone, nine people died in car accidents over the Thanksgiving holiday, according to the Missouri State Highway Patrol. The state saw a total of 587 car accidents, which caused 108 injuries. Fortunately, none of the fatalities occurred on Thanksgiving Day.

Last year, Missouri saw 17 deadly car accidents during the Thanksgiving holiday, with 1,364 accidents reported.

In Montana, a couple from Nebraska and their two young daughters were found dead in their vehicle on the Friday after Thanksgiving Day. Their vehicle veered off the road on Thanksgiving morning after hitting a median, flying off an embankment, striking a bridge support pillar and landing nose-down in the creek.

Authorities suspect that speed may have been a factor in the deadly crash.

The family’s vehicle was discovered in a Montana creek at 8pm on Friday, several hours after they were expected to arrive in Ekalaka, Montana to spend the holiday with their family. They were less than 15 miles from their last known location.