This is a great indicator of Americas decline as a world power. Civics isn’t taught in school anymore and people have become apathetic. In large ethnically diverse overcrowded cities where people don’t know each other they simply don’t care about people. If this had happened in Florence I feel for certain more people would have helped sooner.
Another cause is the fact that most people are rushed for time and the simply don’t pay attention or don’t care. This is a sign of humans over populating the earth.