Authorities say there were no signs of foul play, but the circumstances are “suspicious enough” to warrant a full investigation into the cause of death.

Santa Fe County Sheriff Adan Mendoza told NBC's “Today” show that investigators were trying to sort out conflicting stories about the doors. He said several doors were unlocked and a rear door was open, which allowed two dogs that survived to go in and out. He also said he thinks the front door was closed but unlocked.