An infant was killed and the baby’s mother was critically injured early Sunday when a private ambulance sped through a red light in Frankford and crashed, according to Philadelphia police.

At about 5:15 a.m., a privately operated ambulance transporting the mother and infant sped through the intersection of Torresdale and Harbison Avenues, colliding with a sedan, according to a police account. The force of the crash ejected the mother and baby through the ambulance’s windshield, police said.

Police said the ambulance was “not operating in emergency status” and did not have its lights or sirens on. The driver — a 51-year-old man who has not been publicly identified — will face driving under the influence and other charges, police said.

The infant, identified by police as Marian Harris, was pronounced dead at an area hospital. The mother, who police did not name, sustained severe head trauma.

A police spokesperson said the medical examiner’s office will determine the child’s cause and manner of death.

Before the crash, officers responded to a call about an unresponsive infant at a home in the 6600 block of Ditman Street. According to police, family members left the residence in a private ambulance to take the child to a hospital.

The ambulance is operated by Ambulance Express, Inc., which also does business under the name Medstar EMS, according to a list of the city’s licensed EMS agencies.

When reached by phone Sunday afternoon, a representative for Medstar EMS declined to comment.

Police said the investigation is ongoing, and no additional information was immediately available.