Hong Kong police have alleged unsafe scaffolding and foam materials used during maintenance work may have been behind the rapid spread of a devastating fire at a group of residential tower blocks that has killed at least 55 people and left almost 300 missing. Firefighters were still battling to reach residents who may be trapped on the upper floors of the Wang Fuk Court housing complex on Thursday due to the intense heat and thick smoke generated by the fire. Authorities said the death toll had reached 55, with 45…