Detroit police say Steve Utash, 54, was attacked by a group of 10 or 12 men. Investigators arrested a 17-year-old and a juvenile who were scheduled to be arraigned Monday.
Utash, a tree-trimmer who lives in suburban Clinton Township, stopped and got out of his truck after he hit a boy last Wednesday. Police said David Harris, 10, walked in front of Utash's pickup.
Harris suffered a broken leg but was less seriously injured than Utash was by the beating. Utash was placed in a medically induced coma.
Someone also stole a bag holding Utash's cellphone and wallet from his truck, police said.
Mayor Mike Duggan and City Council President Brenda Jones released a joint statement Friday asking Detroit residents to remain calm durng "this emotionally charged time." They said Utash "had done the right thing" by stopping.
"This senseless vigilante style attack is not the essence of who we are as Detroiters and will not be tolerated," he said.
More than $100,000 had been contributed for Utash by Monday on gofundme.com. Mandi Emerick, one of Utash's three children, said givers have been more generous than she expected.
Emerick was optimistic about her father's chance of recovery.
"The doctors said it would be a few days before they can start taking him off the tubes and things,” she told the Detroit News. “They said the best thing for him is a quiet room and sleep so he can heal.”