BROWNWOOD, Texas (AP) - Authorities in Central Texas say three relatives on a hunting trip are believed to have died of carbon monoxide poisoning inside a box trailer that was converted into a cabin.

Brown County Sheriff Vance Hill says propane heaters were used to keep the cabin warm but the structure didn't have proper ventilation. He says there was no way for the poisonous fumes from the heaters to escape.

Names of the victims, who were found Saturday, haven't been immediately released.

The trailer was on a ranch between Brownwood and Bangs, about 100 miles (160.93 kilometers) west of Waco.

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