Cause of death is carbon monoxide■ORVISTON — The “suspicious” death of a Petersburg woman has been termed “consistent with carbon monoxide poisoning,” according to Centre County Coroner W. Robert Neff.Mrs. Margaret Louise Butler, 34, of Petersburg R.D. 1, was found dead Sunday at 6 p.m. in a truck parked along Woods Road atop Orviston Mountain in Curtin Township. Mrs. Butler was found with her estranged husband who was alive but unconscious, police said.Clifford Allen Butler, 30, of Howard R.D. 1, was taken in the Mllesburg ambulance to the Mountainview Unit of the Centre Community Hospital. He is still listed in serious condition in the hospital’s intensive care unit suffering from dehyrdation. A hospital spokesman said that Butler is in a semiconscious state and is taking some liquids.Neff said that there were no bullet wounds or other marks on Mrs. Butler’s body. A carbon monoxide test will have to be run to make sure that it was carbon monoxide poisoning, he noted.Although the manner of the death has to be determined, the coroner said thatsuicide or murder could not be ruled out. However, he said he has no charges to file against anyone at this time.Neff said that Mrs. Butler’s body had started to decompose, and he suggested that she died sometime Wednesday or Thursday of last week. He explained that the body would not begin to decompose before 24 hours. He said that an investigation is being made to determine if Butler was in the truck that long also.A spokesman at the hospital said if Butler were in the vehicle since last week without fluids it could account for his dehydration. He was also unconscious when he was taken to the hospital, it was reported. Neff said that Butler may be suffering brain damage and may be unable to answer questions.State police report that they have been unable to question Butler concerning the incident but are continuing their investigation. A spokesman said that rto charges were being brought against Butler “at this time.” The 1974 Ford truck has been impounded, police said.