( CNN ) -- Noah and Connor Barthe , the two boys apparently killed by a 100-pound African rock python in Canada , died from asphyxiation , according to preliminary autopsy results . `` While we now have some preliminary information , investigators still have to wait for other test results to come back and for the final report , '' Sgt . Alain Tremblay of the New Brunswick Royal Canadian Mounted Police said Wednesday . `` We recognize that this has touched the hearts of people across the world and that people want to know how this could have happened . Our investigators are looking at all aspects of this tragic incident , and that will take some time , '' he said . Noah , 4 , and Connor , 6 , were found dead Monday morning . Sometime before dawn , the snake came crashing through the ceiling of the apartment where they were spending the night . The apartment was the home of Jean-Claude Savoie , a family friend whose Campbellton , New Brunswick pet store was downstairs . Tremblay said the python was kept upstairs in a custom-built glass enclosure similar to an aquarium . The cage reached the ceiling , and the snake was somehow able to crawl through a vent into the building 's ductwork . It was above the living room , where the boys were sleeping , when the ceiling fell in . The snake was found in the same room as the boys , Tremblay said . He would provide no further details . He said the RCMP is conducting a criminal investigation but would n't discuss possible charges . `` Obviously , it 's not a standard or regular case , '' he said . `` It 's very traumatic for the family that this happened . But for the police , this is an investigation where there 's a loss of life , and our approach to analyze a scene is almost identical , although here we 're dealing with a reptile . '' Canadian broadcaster CBC reported that the python was between 11 and nearly 15 feet long and weighed more than 99 pounds . It was euthanized . The necropsy showed the snake was in good overall health , Tremblay said . Deaths caused by large constrictor snakes like pythons are fairly rare . The Humane Society documents 17 people who have died in incidents in the United States related to the snakes since 1978 , 12 of them since 1990 . CNN 's Matt Smith , Jethro Mullen , Dana Ford and Kevin Conlon contributed to this report .
Noah and Connor Barthe , aged 4 and 6 , were found dead Monday morning . They had been at a sleepover at an apartment above a pet store . The python believed to have killed them has been euthanized . Comment: