Editor’s note: This story has been updated to reflect the new time of the incident that was released by police.

SUMTER, S.C. (WBTW) — Two men and three children are dead after what authorities in Sumter said appears to have been a domestic-related shooting.

A former soldier shot and killed three children as they slept Tuesday night while their mother frantically sought help before killing himself, authorities said.

Charles Slacks Jr. also killed an Army soldier who worked with the children’s mother and happened to be at the home, Sumter Police Chief Russell Roark said at a news conference Wednesday.

Slacks shot the co-worker in the backyard as the mother tried to stop him, pushed past her to go upstairs and shot the children, ages 5, 6, 11, in their beds, the police chief said.

“Little children were sleeping in the comfort of their own bed,” Roark said.

It happened just before 10:30 p.m. Tuesday on Whitetail Circle, Sumter police said in a Facebook post.

Slacks and the woman were divorced, but he still had a key to the Sumter home and let himself in around 10 p.m. Tuesday, Roark said.

The mother’s cellphone was upstairs charging, so she ran to see if her co-worker had his phone where she could use. She heard the gunshots, came back inside and saw her ex-husband at the top of the stairs, where he shot himself, Roark said.

The soldier killed had no relationship with the woman outside of work, and investigators haven’t figured out why Slacks came to the home or whether he was supposed to have a key, Roark said.

“Anybody who has children — anybody who has empathy toward a child dying so violently could understand how that mother is feeling,” the police chief said.

The identity of the soldier killed has not been released because officials are still trying to determine his next of kin, Sumter County Coroner Robbie Baker said.

“It was a long night. This was just an awful thing,” the coroner said.

Slacks was a civilian assigned to U.S. Army Central at Shaw Air Force Base, while the solider killed was also assigned there, according to information from the Army.

The Sumter School District is grieving the loss of three students, including two siblings who attended Millwood Elementary School and a third who attended Alice Drive Middle School, Superintendent William Wright said in a statement.

State Sen. Thomas McElveen, a Democrat who represents Sumter, is a young father of three himself and led the state Senate in a moment of silence.

“As a father, I am absolutely nauseated up here talking about it,” McElveen said.

The Associated Press contributed to this report.