(CNN) -- Two men charged in the deaths of three children run over during a carjacking last month will be charged with another count of murder after the children's mother died, prosecutors in Philadelphia said Friday.
Cornelius Crawford, 22, and Jonathan Rosa, 19, now will face four counts of second-degree murder and conspiracy in connection with the July 25 incident, Philadelphia District Attorney Seth Williams said.
The pair are also charged with kidnapping, aggravated assault and sexual assault after allegedly carjacking a 45-year-old real estate agent at gunpoint and sexually assaulting her as they drove around the city with her in the backseat of her SUV, police said.
When the stolen Toyota 4Runner blew a tire, the driver lost control and it careened into a street-corner fruit stand. It struck and killed 10-year-old Thomas Reed, 7-year-old Terrance Moore and 15-year-old Keiearra Williams, Homicide Capt. James Clark said.
The SUV also hit the children's mother and a pedestrian. The mother, Keisha Williams, 34, died Thursday, prosecutors said.
The carjacking victim was taken to a hospital after the accident in stable condition. A police spokesman said Friday the woman continues to recover from the physical and mental trauma of her ordeal.
After the SUV wrecked in a vacant lot, Crawford and Rosa fled. Two days later, Crawford, a convicted felon, was arrested without incident and Rosa turned himself in, Clark said.
A message left for Rosa's attorney Thursday was not immediately returned. It was not clear who is representing Crawford.
"My heart continues to break for the family and friends of Keisha, Keiearra, Joseph and Terrance," District Attorney Seth Williams said in a statement. "The thoughts and prayers of my office continue to be with everyone affected by the senseless crimes that occurred on July 25th."
Keisha Williams and her family, who lived just around the corner from the fruit stand, were working there on the day of the carjacking to raise money for a local garden, police said at the time.