A 2-year-old boy was killed in a house fire near Detroit Lakes early Sunday, according to the Becker County Sheriff’s Office. Three others were hospitalized.

Around 12:35 a.m., the Sheriff’s Office received a call about a house fire at 23096 Duffney Road, about 9 miles northeast of Detroit Lakes. At the time, two people were still trapped in the house. When deputies arrived, the house was fully engulfed and one child was missing.

According to an initial investigation, children in the basement heard smoke alarms and saw flames once they got to the main floor. A stairway leading to the upstairs bedrooms was blocked by flames and the children’s parents escaped through a second-floor window. When the father realized the 2-year-old was unaccounted for, he and another son went back into the home to search. The 2-year-old was later found dead.

An man was airlifted to a Fargo hospital for smoke inhalation and a woman and 5-year-old girl were airlifted to a Minneapolis hospital for smoke inhalation and burns.

The investigation into the fire is ongoing.