When considering whether a coin dropped from the top of the Empire State Building would kill someone you must take physics into account and not simply assume that a small, hard object would be lethal.
Coins may be relatively heavy due to the density of metal, but this does not mean that they would fall any faster, and therefore more lethally, than an object of the same size.
In one famous story, the Italian scientist Galileo dropped two round objects of equal size but of different mass, let's say an apple and a cannon ball, off the Leaning Tower of Pisa to measure the difference in time it takes to hit the ground. They both hit the ground at exactly the same moment even though the cannon ball is so much more dense. You may also have seen the famous video of the astronaut dropping a feather and a hammer.
So would a coin dropped from the top of the Empire State Building kill someone below? The answer is no.
For any object, at a particular speed, the drag from the air will at some point equal the gravitational pull. This point is called terminal velocity, and is when the object ceases to accelerate. The object reaches a constant speed.
The terminal velocity for a coin is 67 miles per hour, a speed which is not fast enough to cause lethal harm to a person. Although this is proven when Greg Foot has a coin fired at him at 67 miles per hour in The Secrets of Everything, it still caused some damage and would cause more serious damage if the coin hit a more sensitive area, such as his head.