EAST ST. LOUIS, Ill. — Authorities said they arrested the woman in St. Louis as she sat with a shotgun on a bench outside KMOV-TV.

Officers in nearby East St. Louis, Ill., responded shortly before to reports of shots fired and found the bodies of a 4-year-old girl and 5-year-old boy in a bedroom of the family’s apartment, state police Capt. James Morrisey said.

Autopsies on Thursday determined that each child was shot once in the head at close range with a shotgun and died instantly of the “devastating” injuries, said Danny Haskenhoff, St. Clair County’s chief deputy coroner.

The woman’s 8-year-old son managed to escape unharmed and was in a relative’s custody Thursday, Morrisey said.

The shooting marked the latest deadly outburst that victimized children in the struggling city of East St. Louis, evoking memories of a 2006 case in which Tiffany Hall killed pregnant best friend Jimella Tunstall, cut

Tunstall’s fetus from the womb and drowned Tunstall’s other three children. Those childrens’ bodies were later found stuffed in the washer and dryer of the Tunstall family’s apartment.

Hall is serving four life sentences in the killings, as well as a 60-year term linked to the fetus’ death.