VIENNA, (AP) _ A fire burned a house to the ground in Austria early Sunday, killing four young sisters who were trapped in a small upstairs room, media reported. Their parents escaped.

The father of the girls _ an 11-year-old, a 10-year-old and 8-year-old twins _ told police they were awake when the fire started but were unable to get down a ladder from their tiny sleeping loft, the Austria Press Agency said.

The father, identified only as Andreas A., raised the alarm immediately after the fire broke out, and 34 firefighters arrived quickly but were unable to save the children from the burning building, it said.

The children's mother was hospitalized with second-degree burns, and both parents were reported to be suffering from shock.

The fire was being investigated, Major Karl Kuhn of the police in the Lower Austria province said, but a kerosene stove used to heat the tiny house was thought to be the cause.

The couple used the house on weekends. Josef Sahm, mayor of the small community of Reisenberg, about 25 miles northeast of Vienna, said they had lost a young son about two years ago.