I actually think he died first- because when they got there, the reports that the first on the scene (firefighters) gave were that they found "three unconscious adults" and Mr. And Mrs. were removed first, and then Vera. Then they say there were no apparent signs of life and the mom and dad were pronounced dead on the scene after that. Then lifesaving attempts were made on Vera, at the hospital when there was no success in reviving her, she was pronounced dead.
If phillip died last, there could have been the same wording with him but he was described as having been "believed to be phillip savopoulos the male child of mr. and mrs. s" (paraphrased)- see pages 4/5 of this document
http://www.documentcloud.org/docume...n-dellon-dennis-charging-papers-may-2015.html
They also mention that the fire is believed to have started in phillips bedroom- and the fire was basically contained to that one room, and closet, with minor extension to the adjacent bathroom.
His COD was sharp force trauma and thermal (fire)
The adults were found in an entirely different room, COD for them was blunt force and sharp force trauma.
So in light of that, and that they couldn't pronounce Vera dead and tried to save her at the scene, that phillip was dead first, at the start of the fire. Gasoline was used. Gasoline explodes (see also, broken front windows , glass blown out when the gasoline was ignited)
And since the fire with that accelerant can cause temps of 1000 F- and phillips COD was thermal partially, I would reason that his life (hopefully quickly) ended when he was lit on fire.
There is a CFI on this board who talked about the fire yesterday. Maybe he can elaborate what he thinks?