Weight calculation error behind Tokyo construction site accident

See my old teacher Mr. Gibbs was right. Math is important.

A very sad and avoidable accident led to the deaths of two workers.

There must be a big engineering mistake in the weight calculations. They are supposed to hava a factor of safety to handle more weight than the total weight of the material.

Mistakes happen, construction work has always been hazardous. Get it right, make it right, and move on !