How did Americans react to the event in my lai?

Answer 1

To review the background for readers who don't remember, this happened during the Vietnam War. An American patrol led by Lieutenant Calley was passing near the village of My Lai, and they were fired on. Most likely the Viet Cong soldiers merely entered the village from the other side, shot at the Americans, then retreated the way they came in. Nobody knows whether any of the villagers themselves took part one way or the other. The Americans took the village and proceeded to kill everyone there--men, women, and children.

When the story first became public and people heard that Lieutenant Calley might be court-martialled for killing civilians, there were two main reactions among Americans: Some were horrified at the slaughter of civilians, and others thought Calley should be rewarded, not punished, for killing "the enemy." As the investigaton proceeded and more facts about exactly what had happened filtered out, more people came to be shocked at the brutality of the American soldiers' reaction to an attack by unknown persons.

Answer 2

They were shocked at the event and dissatisfied with the investigation that followed.