From the Detroit News:
An Arkansas family was visiting a relative in Washtenaw County for the holidays Saturday when a house explosion killed a mother, father and their two adult children while leaving two others hospitalized. Hope Bragg, a 51-year-old youth instructor with the University of Arkansas' 4-H Youth Development program, and her family were in Michigan to visit Bragg's father Rich Pruden, 72, who lives in the 8200 block of Winters Lane in rural Northfield Township. Bennett said Hope Bragg, her husband Don Bragg, 53, and their adult children Kenny and Elizabeth Bragg were killed in the 3:48 p.m. explosion that sent debris flying for two acres and could be heard 9 miles away. A third adult sibling, Stephen Bragg, and Pruden were expected to survive. The family, which lived in Monticello, Ark., had just left Rhinelander, Wis., where they'd visited Don Bragg's parents. They always split the holidays up between the two parents. Bragg worked as a project leader for the U.S. Department of Agriculture, where he studied ecosystems. Kenny Bragg, was set to graduate from Michigan Technological University in the spring with a degree in industrial heritage and archeology.
Nobody knows what happened inside the house, and the family isn't making guesses; they're waiting to hear from the investigators.