(Sioux City, Iowa – KTIV) – Authorities in Sioux County say at about 5 a.m. on Monday, Sept. 1, firefighters were sent to a home on 430th Street, 2.5 miles northwest of the town of Granville. According to Sioux City television station KTIV, when they got to the scene, firefighters reported heavy smoke coming from the home, and assistance was called in from nearby communities.

A statement from the Granville Fire Department said “Fire personnel discovered four persons inside the residence in critical condition; they were transported by ambulance services to Orange City Area Health,” stated the Granville Fire Department in a press release.

According to the fire department, one person died from their injuries at the Orange City hospital. The other three were sent to specialty units at other hospitals for further treatment. At one of these other hospitals, another one of the victims died from their injuries.

The Sioux County Sheriff’s Office confirmed today (Tuesday), that a third person has died from their injuries. Authorities have not released the current condition of the other individual. The identities of all four are not being released as authorities continue their investigation and notify family members. What caused the fire is still under investigation.

M-O-C Floyd Valley High School faculty and staff as well as local clergy will be available at the high school in Orange City this week to offer support and talk with anyone connected to or affected by the tragedy.