I was walking by this construction site above with my friend Lao Meng when we heard a humongous explosion and then saw large metal sharples the size of car tires flying onto the street. We both just stood there watching everyone panic and running away from the site. We didn't see any pieces of metal land on anyone; the metal flew over everyone's heads and onto the street. And we were safe in the end. It was shook us up a bit and reminded us that it's quite normal for several deaths to be associated with each construction project.
We couldn't get any answers about what happened. Construction sites are very private about what goes inside their walls. If they see you taking pictures, someone will come up to question you on why you're taking photos and harrass you.
We will probably never know if any migrant worker was injured or killed. There were no reports of this in the newspapers the next day. From my apartment building I could see a big hole had been blasted out on the site and they had to tear down several levels of concrete. It appears that they had to start all over again after the blast.
Chinese construction companies are notorious for creating shoddy buildings. Some apartments begin to show problems with the first few years. But construction companies often change their names, so it becomes difficult to hold the company responsible for the building. Most of these buildings are only made to last 25-30 years, even though the government requires them to last 50 to 100 years. According to the Land Administration Law that was last modified in 1988, people only have residential rights to buildings for 70 years from date of purchase.
Below are some pictures of what the area surrounding a construction site loosk like - the walls block pedestrains from seeing the site and the sidewalks are filled with dust. The walls are usually plastered with advertisments symbolizing the success of construction projects.