"The Mountain Meadows Massacre stands without a parallel amongst the crimes that stain the pages of American history. It was a crime committed without cause or justification of any kind to relieve it of its fearful character... When nearly exhausted from fatigue and thirst, [the men of the caravan] were approached by white men, with a flag of truce, and induced to surrender their arms, under the most solemn promises of protection. They were then murdered in cold blood."
-William Bishop, Attorney to John D. Lee

For those interested, there are some excellent online sites offering details of this controversial event.

The Baker-Fancher party from Arkansas was traveling along the Old Spanish Trail on its way to California and stopped here at Mountain Meadows to rest, a favorite resting spot of all who traveled along the trail. On Sept. 7 they were attacked by a band of Mormon militia and Paiutes. Records show that they had been ordered to not allow any emigrants to cross. The massacre occurred as the Mormons were escorting them to Cedar City. In all 120 innocent people were murdered. Only 17 children were spared.
A memorial stands at the spot where they were originally attacked. Many of the murdered settlers were buried under this rock cairn erected by the US Army who arrived at the site after hearing of the massacre.
It has only been within recent times that the Mormon Church has really talked about this incident and it still claims no responsibility for it.
The only person punished was John D. Lee who was was found guilty by a jury and chose to be executed by a firing squad. The execution took place here at Mountain Meadows.