The Brooklyn woman whose 6-year-old son died when she crashed her car while driving the wrong way down a street claims she lost control of her vehicle because her brakes were not working, police sources said Thursday.

Little Jerry Louisamard was not in a booster seat at the time of the crash Wednesday, the sources added, but it wasn’t immediately clear if he was wearing his seat belt.

Louisamard’s 44-year-old mom was driving with the boy in the back seat shortly after 4 p.m. when she plowed her family’s 2013 Toyota Highlander just a half-mile from their Canarsie home, police said.

She was traveling in the wrong direction down Seaview Avenue and crashed into an unoccupied, parked 2017 Nissan Rogue, prompting the Nissan to slam into a second parked vehicle, cops said.

Investigators believe speed played a role in the crash, sources say.

Louisamard was rushed to Brookdale Hospital, but could not be saved.

His mother, who passed drug and alcohol tests, was also taken to the hospital in stable condition, police said. She remained hospitalized on Thursday morning, relatives told the Post.

No one was immediately arrested or charged, and the incident is still under investigation.

Additional reporting by Ruth Weissmann