gathered and the actions of josh and how fast this fire has burnt, we believe this was intentional. >> reporter: the home exploded moments after a social worker brought 7-year-old charles and 5-year-old braden for a supervised visit with their father. powell is the person of interest in the disappearance of his wife from their utah home. the children lived with susan's parents, who say the boys didn't want to visit their father sunday. >> they seemed to be losing and in going to see him. >> reporter: a judge denied josh powell custody of his sons wednesday. powell sent a letter to his lawyer wednesday, saying, i'm sorry, goodbye. >> it's just senseless. senseless. to slaughter two innocent children. >> reporter: an attorney for the grandparents say they are starting to remember what happened the night their mother vanished. >> they had been camping. their mother had been in the trunk. and that later, their mom and dad walked out into the desert. and mommy got lost. >> reporter: fire...