"Now I can't stop thinking if our building isn't safe either. They said there's something wrong with the fire alarms, and all these towers are old," Ran said.

Ran said she made a point of opening the window to show her children the fire scene. "I explained to them what I was about to do and why mommy had to help and that in times of crisis, everyone must all do their part, with a loving heart."

Before Ran's arrival at the shelter, a basketball court-sized plaza near the fire scene was covered with donations of winter gear, pork buns, instant noodles, water, lights, toiletries and even pet food.

Preliminary investigations showed the fire started on a lower-level scaffolding net on one of the buildings. It then spread rapidly as the windows were covered by Styrofoam boards to the neighboring six houses, said Hong Kong's Secretary of Security Chris Tang Ping-keung on Friday, when the fire was finally extinguished after 43 hours.

Police also said they had been looking at the highly flammable foam panels. "The blaze ignited the foam panels, causing the glass to shatter and leading to a swift intensification of the fire and its spread into the interior spaces," Tang said.