Philadelphia – a 5-year-old revealed to the police that he was playing with a lighter before the fire broke out, the police determined on Tuesday.

The last Wednesday’s rowhouse fire incident that killed 12 including 9 children, was likely caused by a 5-year-old boy who set fire to a Christmas tree as he was playing with a lighter, said officials on Tuesday.

The rowhouse caught fire just before dawn, swiftly engulfing the 2nd story of the house residing in the state’s Fairmount neighborhood. The two people who survived the incident included a 5-year-old boy who later told the police investigating that he was playing with a lighter, making the first theory about the incident’s cause.

The case investigators attempted to find other sources that could disregard the statement given by the kid, who allegedly was the only person present at the part of the house where the fire began, according to Philadelphia Fire Commissioner Adam Thiel.

“We are left with the words of that 5-year-old child, that traumatized 5-year-old child, to help us understand how the lighter and the tree came together with tragic consequences,” the commissioner said. “We have disproved any other theories.”

When the blaze caught, 14 people were in the rowhouse, not 18 as previously reported and all of them were on the third floor in their bedrooms except for the 5-year-old kid. Twelve people died, including 3 sisters and 9 of their daughters and sons. Only two people survived, the 5-year kid and a man who is currently hospitalized jumped from a window on the third floor.

The Tuesday’s findings came following a preliminary investigation conducted by the Fire Marshal’s Office and the state’s other federal agencies, said the authorities.

The housing authority officials reported last week, “that the upstairs apartment had been inspected in May, and that all of the smoke alarms, which were battery operated, had been found working at the time.”

Out of the seven alarms that should be activated, only 1 was working and that too was attached in the basement and rang too late.