A baby girl has died after an ambulance transporting her to hospital collided at speed with another vehicle, sending the child and her mother through the windshield, authorities have said.

The crash occurred around 5 a.m. Sunday morning in the Frankford area of Philadelphia after the ambulance ran a red light, law enforcement said. The mother and child were being taken to hospital in the private vehicle, reportedly driven by the infant’s 51-year-old grandfather.

Officers had responded to a 911 call about an unresponsive infant at a nearby residence but were told that a family member was taking the child to hospital.

The ambulance, belonging to Medstar EMS, was traveling at “a high rate of speed” and not operating its lights or siren, police said. After running the light, the vehicle collided with a Honda Accord.

The force of the crash sent both the mother and her baby through the windshield and into the road, according to police. Philadelphia Fire Department medics transported the pair to Albert Einstein Medical Center, where the infant was pronounced dead at 6:17 a.m.

The mother sustained severe head trauma and remains in critical condition Monday.

“I hope the lady’s OK, I hope she makes it,” Tyron Herring, who lives near to the scene of the crash, told CBS. “Even though her child is gone, her life is still important.”

The Honda driver, a 25-year-old male, refused medical treatment at the scene.

The ambulance driver was taken to Jefferson Torresdale Hospital and will face charges including DUI. Philadelphia District Attorney’s office said they had not been contacted by police regarding charges against him, CBS reported Sunday night.

The Independent has contacted the DA’s office for an update on any charges, and MedStar EMS for comment. The company declined to comment to CBS and said it is conducting its own investigation.

Philadelphia Police Department said the investigation remains ongoing with the Crash Investigation Division.