No one is Monday morning quarterbacking, no one has claimed to know what caused that bldg to fall. The forensic engineering expert in the clip was telling how the investigation would proceed, what signs they would be looking for in order to arrive at a conclusion. You should watch it, it is quite interesting to the non-engineer types.

Just a few basic things that apply to construction everywhere. Salt, (calcium) and heat are two enemies of concrete. Forty years ago in some cases, calcium was added to concrete to help it set up quickly. This action attacked the rebar in the mix. Chemical additives were invented some years back that can be added and the rebar is not under attack. There are ways to test the concrete that is in the pile to see what additive was used if in fact there was any at all.

Soil compaction and grading are also key ingredients to prevent disasters like this. Also using leftover concrete from the first delivery a truck makes in the next load deteriorates the strength and durability of the 2nd load. Remember the ceiling falling in on The Big Dig in the North East. Leftover Concrete.

Payoffs to inspectors to look away and sign that things passed was a very popular thing 20 to 40 years ago to help keep costs down. Sadly the poor people paid the price for one or more of the things I mentioned. God Help the Families.

I can imagine a sinkhole taking down one of those matchbox rental apartments in TV.