It happened around 12:10 p.m. on Marshall Road at Littlecroft Road in Upper Darby Township, Delaware County.
One of the boys is listed in critical condition while the other two are in stable condition.
All three are 7th graders at Beverly Hills Middle School. Two are 13-year-olds and the other is a 12-year-old.
Action News has learned two of the boys involved are Jemel Brunswick and Tyler Lowery. The last name of the boy in critical condition is Beyene. That child's father, named Beyene Beyene, says the child is in a coma.
"They want to do something about his head," said Beyene Beyene. "He broke his arm, he broke his leg. Then, they told me, they're going to see what's going on. The main problem... is his head."
Upper Darby Police Superintendent Michael Chitwood says two boys were standing at a curb on Marshall Road Tuesday afternoon waiting to cross a street. He says that's when a 42-year-old woman swerved to avoid a traffic jam, went across three lanes of traffic, hit the two boys with her car, then kept going.
Chitwood says the driver then hit a third boy about 15 yards down the street.
Chitwood said the driver then hit a car, slamming it into a parked car, and eventually came to a stop more than 25 yards down the road.
The children were out at the time because the school had early dismissal.
At least one witness said he couldn't believe his eyes.
"I heard three crashes and yelled 'Oh my God!'" said Jean Greaseau. "I looked toward the door and seen the kid flying toward the wall."
One of the boys was knocked out of his shoes, through the parking lot of an Auto Zone, then he hit the store wall.
A second boy was tossed more than 30 feet up Marshall Road. The third boy was thrown to the ground, right behind Greaseau's car.
"The one behind my car was conscious. He was moving, he gave out a phone number, he gave out his name" Greaseau said. "The one on the street was just moaning, and the one by the wall wasn't moving at all."
Chitwood said that the woman will face charges pending toxicology results.
"Obviously it was reckless. Certainly, as she tried to get away, it was felonious," he said. "She's locked up right now."
Witnesses say the driver was hysterical when she finally stopped, repeatedly saying she "could not stop the car."
