A very big fire happened last week in a Hong Kong housing area called Wang Fuk Court. The fire killed 151 people. Many more people are still missing. It is the worst fire in Hong Kong in over 70 years.
The buildings were covered with special nets for repair work. Police say the nets were not safe. Tests showed the nets could burn very easily. Officials say workers put the bad nets in hard-to-see places. They did this to avoid checks. The fire spread very fast because of this.
Police have arrested 13 people from the building company. They think these people are responsible for the deaths. People living there had complained about the repair work before, but no one listened.
Police also arrested two people for things they wrote online about the fire after it happened. This has made some people upset.
Now, Hong Kong is very sad and people are asking serious questions about building safety rules.