Three people were killed in separate traffic crashes that happened within about an hour of each other on the South Side and in south suburban Hazel Crest during a winter storm that raked the Chicago area early Saturday.

About 2:10 a.m., a vehicle with four occupants struck a tree in the 16900 block of Wood Street, ejecting a passenger from one of the rear seats, according to Hazel Crest police.

The ejected passenger and the driver were both pronounced dead, officials said.

Two other passengers were hospitalized. Their conditions were unknown.

About an hour earlier, state troopers responded to a single-vehicle crash on the Dan Ryan Expressway (I-94) near 75th Street, according to Illinois State Police.

A Chevrolet Equinox tried to exit at 75th when it lost control and struck a lightpole at the top of the right embankment, state police said.

One person was pronounced dead at the scene, officials said.

It wasn’t immediately clear what caused either crash, but they occurred as Chicago’s first major winter storm of the year left half a foot of snow in parts of the city.

O’Hare Airport recorded 6.7 inches of snow while 5.8 inches were recorded near Midway Airport, according to the National Weather Service.