A Vermont police chief says he believes three children drowned accidentally in a frigid river. Chief Trevor Whipple says it appears the two brothers and a female friend were "playing around" in the area of the brook, which he said is lined with "very slippery rocks." The bodies of 13-year-old Justin Nutbrown, his eleven-year-old brother Joshua and their eleven-year-old friend Allison Hansen were found in the river today. Police began the search in Barre late last night after the kids didn't return from playing in the woods. Officials say they may never know if one child fell into the water and the others attempted a rescue or whether they all slipped into the water. Autopsies are planned.