Fifty vehicles crashed in a massive pileup Wednesday morning on an icy Kennedy Expressway near North Avenue, sending over a dozen people to hospitals with minor injuries.

All lanes of the expressway were closed for hours, while Illinois State Police said it responded to more than 80 more crashes on Chicago-area expressways that were “covered in sheets of ice.”

Three semitrailers and 47 other vehicles piled up about 4:40 a.m. on the Kennedy’s inbound lanes, state police said.

Fourteen people were taken to hospitals, according to the Chicago Fire Department. None of the injuries were life-threatening. Thirty-two other people involved in the crash refused transport to hospitals.

“Numerous accidents still [being] reported due to low traction around the city,” the fire department said Wednesday morning on Twitter. “Do not use Kennedy at this time. Be aware of low traction on all expressways and some surface streets.”

State police haven’t said what caused the crash, but said weather conditions were a contributing factor.

Troopers responded to 85 other crashes Wednesday morning on Cook County expressways, state police said. Only 18 of those crashes left people with injuries, which were all minor.

In one series of weather-related incidents, state police reported 11 crashes shortly after 4 a.m. on I-190 near O’Hare Airport. Westbound lanes were shut down for two hours, and one person was injured.

The Illinois Department of Public Transportation, which plows and salts Chicago expressways, deployed about 70 salt trucks Wednesday morning, which was “an appropriate response for the department for a weather event of this magnitude at this time of year,” IDOT spokeswoman Maria Castaneda said in an email.

While there was little snow, low temperatures and wet conditions caused black ice to form on that portion of the Kennedy, Castaneda said. Low traffic volume and higher traveling speeds may have also led to the spinouts and crashes Wednesday morning, she said.

Light snow began falling in Chicago after midnight, with a total nighttime accumulation of less than a half inch, according to the National Weather Service. Along with snow, temperatures dropped into the 20s and 30s overnight, contributing to slick roads and icy conditions.

Castaneda said there were very few issues on arterial streets where speeds were lower.

“In areas that were hardest hit, i.e. the Kennedy Expressway and northwest part of the city, we had a full complement of personnel and equipment on the roads,” she said.

IDOT crews had been working since 1:30 a.m., and “those numbers escalated as the forecast changed and the event intensified,” she said.

Castaneda said it is not uncommon to have an early spring snow event that proves challenging for the transportation department.

“We will be closely monitoring and responding as necessary, but we ask for the public’s cooperation if they are driving to check conditions in advance at GettingAroundIllinois.com and slow down,” she said.