Authorities are investigating the deaths of 5-year-old twins — a boy and a girl — after they were found dead Monday inside a New York apartment.

Police responded to a 911 call at 11:20 a.m. local time and discovered the siblings “unconscious and unresponsive” inside the Bronx residence, located near East 175th Street in the Mount Hope neighborhood, the New York Police Department said.

Detectives learned that the pair were sent home sick from school last week and remained home Monday. Their mother, who was also home at the time, reportedly told police that she had found them unresponsive after she finished a shower.

The children were pronounced dead at the scene, authorities said.

The family doesn’t have a history of domestic violence, they added, and no carbon monoxide was detected in the apartment or signs of trauma found on the children.

“At this time, we do not know if there’s any foul play,” NYPD Assistant Chief Benjamin Gurley told reporters.

“When you go up and you see two 5-year-olds laying on the floor unresponsive and cold, at this time of the year, you could imagine what the family’s going through,” Gurley said. “You could imagine what the mother is going through, and the father.”

The NYPD didn’t immediately respond to HuffPost’s request for comment.

The children’s mother was found uninjured but “emotionally distraught,” Gurley told reporters, adding that she was taken to a hospital for treatment.

A cause of death is set to be determined by the city’s Office of Chief Medical Examiner.