PROVIDENCE –– A 12-year-old girl remains unconscious in Rhode Island Hospital’s trauma intensive-care unit after being struck by a hit-and-run driver in Mount Pleasant late Sunday night.

The police have charged the man believed to be the driver, but declined last night to identify the child because she is a juvenile.

Until late yesterday, the police believed the girl, who carried no identification at the time of the crash, was between the ages of 16 and 20 and were scrambling to figure out who she was. Authorities described her and asked the public to call them with any information.

Last night they said the girl had been identified –– presumably by her family.

According to the police, the child was crossing Atwells Avenue at Unit Street alone after 11 p.m. when a car smashed into her. The impact sent the girl into the windshield and over the roof of the car before tossing her onto the street, said police Sgt. Paul Zienowicz.

The driver never used his brakes to avoid hitting the girl and never stopped to check on her after she was struck, Zienowicz said.

A witness gave the police a detailed description of the late-model blue Hyundai and the man at the wheel, the sergeant said.

Moments after the vehicle’s description was aired by the media early yesterday, the police got a tip that the car was in North Providence. Investigators tracked down the suspected driver and the man’s damaged car at his apartment at 7 Brook St., Zienowicz said. The car “matched the description perfectly, right down to the fin” on the trunk, the sergeant said –– and the front end and windshield were smashed.

The driver, Juan Aguirre, 67, also matched the witness’s description, and he was charged with leaving the scene of an accident causing bodily injury and with other traffic offenses. Aguirre was held last night and will be arraigned in District Court today.

Zienowicz said Aguirre refused to speak to the police after he was taken into custody and instead hired a lawyer.

The girl suffered numerous facial fractures and remained unconscious, Zienowicz said.

Police officers and street workers spent yesterday canvassing the neighborhood and the Manton housing projects, asking if anyone knew the victim they thought to be a young woman.

The girl was finally identified late last night.

amilkovi@projo.com