By CLAUDIA LAUER, MICHAEL RUBINKAM and MARYCLAIRE DALE
PHILADELPHIA (AP) — Investigators are looking into whether a 5-year-old who was playing with a lighter set a Christmas tree on fire, sparking a conflagration that killed 12 family members in a Philadelphia rowhome. That’s according to a search warrant application revealed Thursday. City and federal investigators are working to determine the cause of the city’s deadliest single blaze in more than a century. They declined to speculate on a possible cause, adding the fire scene is complex. The fire took the lives of eight children and four adults. Officials have said 26 people had been staying in the three-story brick duplex.