North Carolina ? Investigators are probing whether oxygen tanks, among other possible causes, may have started a fire at an adult care home that killed one person and put more than a dozen in the hospital, authorities said Tuesday.

Citing the oxygen tanks used by some residents of Davie Place Residential Care, officials said “an explosion could have happened” and ignited the blaze late Monday night.

Investigators don’t believe the blaze was arson, assistant Davie County manager Beth Dirks said. Results of the investigation are expected today.

George Minor of Mocksville was killed in the blaze, Dirks said. Four patients were in critical condition at a Winston-Salem hospital. Some of the 15 other patients who had been hospitalized were released, but Dirks said she didn’t know the number.