A 10-month-old severely injured in a wreck last week died Monday, just four days after his mother was killed in the same crash, the Monroe County Sheriff’s Office said.

William M. Foster had been the lone survivor in a wreck that killed his mother, Carole Foster, and Howard Zach, Monroe County sheriff’s Lt. Lawson C. Bittick said in a news release.

Foster, 24, and Zach, 51,  were traveling on Highway 83 when they were killed in a head-on collision, Bittick said. William Foster was properly restrained in a car seat in the back center seat at the time of the wreck.

He was critically injured and taken to Monroe County Hospital, where he was stabilized and flown to Children’s Healthcare of Atlanta at Egleston, Bittick said. He remained at Egleston in critical condition for several days.

“Please keep the families who were touched by this terrible collision in your thoughts and prayers,” Bittick said.

No other details on the crash were released.

In other news:

Police: Paraplegic Zip-Ties, Shoots Stripper with Stun Gun in His Georgia Home