New York Mayor Bill de Blasio says an investigation is underway today after another crane accident.
 
Officials say a 4-ton air conditioner that was being lifted broke free and dropped nearly 28 stories on Madison Avenue by 38th Street Sunday.
 
Chopper 12 was above the scene where officials say glass and metal cascaded down on top of ten people.
 
Amazingly, none of the injuries were life threatening.
 
There have been six crane accidents in New York City since 2008 and 11 people have been killed.