CHARLOTTE, N.C. -- A dangerous driver is on the loose after a hit-and-run crash involving a Charlotte-Mecklenburg Police Department volunteer Monday.

NBC Charlotte learned that the volunteer underwent surgery Tuesday afternoon for a serious leg injury. Investigators said there has never been a case like this before, involving one of their volunteers suffering such a serious injury.

CMPD volunteers are officially called “Citizens On Patrol”, but within the police force they’re simply known as “brothers”.

“It really hits home because he's a brother of ours,” said Sergeant Chris Koppe.

NBC Charlotte talked to CMPD volunteer Bob Riefe, who says he has confidence in his fellow volunteers.

“I know he's got my back, I've got his back,” explained Riefe. “I worry about drivers, I don't worry about us.”

RELATED: CMPD volunteer struck by car in hit-and-run

What happened Monday evening demonstrates the reason for his concern. A CMPD volunteer was hit by a car near Park Road and Hillside Avenue while directing traffic at a crash scene. He was rushed to the hospital with a serious hip injury.

“He was hit by the car, thrown to the ground, and he's actually in surgery as we speak,” said Koppe.

Now, the hit-and-run driver remains out on the streets.

“Our goal is to find out the driver of that vehicle,” Koppe said.

NBC Charlotte learned more about CMPD's volunteer force. Police said those who direct traffic go through an additional 11 weeks of training, twice per week.

“Unfortunately, he did everything correctly; he was still struck,” said Koppe. "In the history of the program, this has never happened, so this is really uncharted territory."

“People who aren't competent aren't allowed in the streets, I feel very confident,” said Riefe.

The volunteer who was hit just graduated from the COP Academy in July.

“We’re taking care of him, we're taking care of his family, and we're going to get them through this,” said Koppe.

Police say the city will pay for the volunteer’s medical costs. If you have any information about the driver you’re asked to call CMPD's Crime Stoppers at 704-334-1600.