PITTSBURGH — Authorities in are working to determine how an underage man obtained the alcohol police say he consumed before a crash that killed a 6-year-old girl.

Police say Travis Grayson, 20, of Millvale lost control of his car Saturday night and hit the Shaler girl and her mother. He is charged with homicide, involuntary manslaughter and other offenses.

Police said Grayson told them he drank 10 beers, smoked marijuana and “was driving like a stupid idiot.”