A 6-year-old boy riding in a booster seat on his way to school Friday was shot dead on a California highway in an apparent road-rage incident.

"Mommy, my tummy hurts," Aiden Leos said moments after being shot in the stomach, his older sister Alexis Cloonan told KABC.

Aiden attended kindergarten at Calvary Chapel in Yorba Linda, according to local reports. He had just celebrated his birthday last week.

Orange, CA - May 21: A crime scene investigator photographs the scene while the California Highway Patrol secures the northbound lanes of the 55 Freeway near Chapman Avenue were a 6-year-old boy was fatally shot during apparent road rage incident Friday, May 21, 2021 in Orange, CA. The suspect fled immediately after the shooting near West Chapman Avenue as police officers and paramedics responded to the gunfire shortly after 8 a.m., authorities said. The boys mother was traveling on the northbound freeway with her child in the booster seat when the shooting occurred, CHP officials said. Witnesses reported hearing a gun shot from a white sedan right before the childs mother pulled her vehicle over to the shoulder. This was an isolated road rage incident, said CHP Officer Florentino Olivera. He said the driver of the white sedan shot into the back of the mothers Chevy Cruze sedan (shown at upper right) and then fled. (Allen J. Schaben / Los Angeles Times via Getty Images) (Getty Images)

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The incident took place about 8 a.m. on the northbound side of the 55 Freeway in Orange while Aiden drove with his mother in a silver Chevrolet sedan. The boy sat in his safety seat in the right rear passenger side of the vehicle. 

The tragedy unfolded when the unidentified mother — who was not injured — reportedly flipped off the driver of a white sedan who had cut her off in the highway’s carpool lane. A passenger in the white car fired off an unknown number of shots, hitting Aiden, reports said.

The frantic mom "picked [Aiden] up and he was bleeding on her, she had blood on her clothes," Cloonan told reporters. "And then he started turning blue, and that’s when the ambulance took him. And that’s the last time my mom saw him alive."

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The boy was pronounced dead at a nearby hospital. Police are searching for the suspects.

"Please help us find who did this to my little brother," said Cloonan.

"It was an isolated road-rage incident between the mom and another driver from a white sedan," California Highway Patrol Officer Florentino Olivera told Los Angeles news station KTLA-TV.

A GoFundMe page created to help Aiden’s mother had already generated more than $40,000 as of early Saturday.

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