Hong Kong firefighters brought under control on Thursday a huge blaze in an apartment complex that killed at least 55 and left nearly 300 missing, while police said its cause could have been a ¡°grossly negligent¡± construction firm using unsafe materials.

Rescuers battled intense heat and thick smoke for more than a day after the blaze erupted as they fought to reach residents feared trapped on the upper floors of the Wang Fuk Court housing complex in the northern district of Tai Po.

The eight blocks of the tightly packed complex have 2,000 apartments home to more than 4,600 people in the financial hub struggling to overcome chronic shortages of affordable housing.