AP – Seven children, including a 7-month-old girl, perished in a fast-moving fire in a Pennsylvania farmhouse while their mother milked cows and their father dozed in a milk truck down the road, police said Wednesday.

No cause or origin of the fire had been determined by early Wednesday morning, but the children’s grandfather, Noah Sauder, told The Associated Press the blaze may have started in the kitchen, where the family used a propane heater. Fire marshals were investigating.