Zeus Killed Asclepius-Why

After being rescued from his mother's womb, Asclepius received his name (Asklepios) meaning "to cut open". As a boy, Asclepius was raised by the centaur Kheiron, who taught him the art of medicine. Asclepius practiced, and became so good at his skill that he could bring the dead back to life. This angered Zeus, as it upset the natural order. Zeus saw this as a crime and destroyed Asclepius with a thunderbolt.
After his death, Asclepius was placed among the constellations as Ophiochus, which means "the Serpent Holder".

Picture: http://www.educ.fc.ul.pt/docentes/opombo/hfe/protagoras/images/asclepius5019.jpg
(See somewhat related post, "Tiber Island-Where")