Updated 05/13/12 – 5:34 p.m.

CHICAGO (CBS) — It’s been a dreadful Mother’s Day for the families of four young mothers, who were all killed when their car slammed into a pole in the Austin neighborhood on the West Side overnight.

The car hit light pole in the 4800 block of West Lake Street at a high rate of speed around midnight. Initial reports said the car may have hit a support column first. Authorities said three women in their 20s were pronounced dead at the scene. They were identified as 21-year-old Tyshyra Hines, 22-year-old Alicia Goston, and 25-year-old Bernadette Harris.

The fourth victim, 21-year-old Ieshia Nelson, was taken to Mount Sinai Hospital, where she was pronounced dead shortly after midnight on Sunday.

The car had been split in two during the crash. Family and friends said all four victims were mothers.

Police are investigating the accident, which happened around midnight.

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Nelson’s mother, Yvette Harris, said Nelson’s 2-year-old son doesn’t know about his mother yet – and she is still wondering how to tell him.

“I took him to his grandparents’ last night, because he couldn’t go to the hospital with me,” Harris said. “And I don’t know what I’m going to say because when I left, he asked me, ‘You going to get Eesh? My mommy?’ I don’t know what I’m going to say.”

Harris said her daughter was the driver and she says the women were on their way to a party.

As for reports that they might have been drag racing, she said she doubts it. She said an eyewitness told her another car, a black Dodge Charger, hit the.

Harris also said her daughter was not doing alcohol or drugs.

She said her daughter was studying to be a nurse and had just turned 21 on May 1.

“She was just starting a new job and her baby was going to day care, and she was happy about it. And this happened,” Harris said.

Hines’ aunt, Pearl Henderson, said Hines worked at McDonalds and had a 5-year-old son.

Several family members said they heard it was possible another car bumped the victims’ car before it hit the light pole. The Chicago Police Major Accident Investigation Unit was investigating the cause of the crash.

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