The athlete's son, Liam Mikael Kowal, was being pushed in a stroller through a crosswalk by his teen aunt in Hawthorne when they were struck by a 72-year-old woman, according to police.
Kowal posted the devastating news on social media.
The crash happened near 133rd Street and Hawthorne Boulevard Saturday afternoon. The suspect, identified as Donna Marie Higgins, tried to flee the scene but witnesses followed her and blocked her vehicle until authorities arrived.
She was arrested on suspicion of felony drunk driving and felony hit-and-run. She was booked at the Hawthorne jail in lieu of $100,000 bail.
A GoFundMe account has been set up to help the family.