Authorities say five children died in a house fire in western South Dakota.

The fire was reported at 4:23 a.m. yesterday at a two-story residence in Spearfish, a town of about 11,000 people.

Spearfish police and fire officials say the victims were believed to be between the ages of 6 and 9 years old. Officials aren’t ruling out that there could be more fatalities, but believe they have accounted for everyone.

There was possibly a sleepover or party happening at the time of the fire, officials told KELO.

Spearfish Fire Chief Mark Sachara says some adults tried to rescue the children and were taken to Spearfish Regional Hospital for treatment of smoke inhalation. Their conditions were not known.

Officials say the house was engulfed in flames when firefighters arrived. A cause has not been determined.