Mayor John Cranley said Kyle Plush's death was "heartbreaking for all of us." He apologized to family members present, including Kyle's father, who found his body the evening of April 10. City council members also offered their thoughts and prayers.
Cranley spoke at a council committee's session called to find out what happened after Plush was trapped by the vehicle's rear bench in a school parking lot.
"Clearly things, regardless of who's at fault, didn't go the way they were supposed to go," Cranley said. "And that is on us."
Plush used his phone's voice feature to call 911 twice from the 2004 Honda Odyssey, but police couldn't find him. The Hamilton County coroner said he died from asphyxiation due to "chest compression."
City officials are examining the response to the 911 calls and possible staffing and equipment issues at the emergency center.
Police Chief Eliot Isaac said there are "many questions to be answered" in the police department's investigation. He said he hopes to conclude it quickly, possibly in 10 days.
He said a 911 operator who had been put on leave following the youth's death will return to work Wednesday, but will not be taking emergency calls as the investigation continues.
In his second call, Plush provided a description of his vehicle while saying: "I'm almost dead." But police said officers in the area didn't have that information. Investigators are trying to determine whether there was an operator error or equipment failure, or both.
The Hamilton County prosecutor also plans a probe.
Honda has said the minivan model had no seat-related safety recalls and that the company has shared information with the National Highway Transportation Safety Administration. Federal transportation officials have said they are in contact with Honda and Cincinnati area authorities.
Kyle's parents Ron and Jill Plush said in a statement last week that their son "embraced life with a passion far beyond his years." They added: "We also have questions and want answers."