In the poem "Out, Out--" by Robert Frost, the poem turns on the word "supper." Describe what happens. Is it an appropriate word in the context?

In this narrative poem by Robert Frost, a boy is using a chain saw to cut up firewood in the back yard. The boy's sister comes and stands next to him and says, "Supper." At this, the boy must have lost his concentration. Perhaps he was startled. When there are loud sounds, even loud music playing, you often don't hear someone approach. Then when the person speaks, you jump because you weren't expecting him or her to be there. In this case, the boy was probably startled or at least distracted by his sister's brief announcement. That was all it took for him to lose control of the chainsaw momentarily. He was probably a little small or young to be handling such powerful, dangerous equipment, for the poem describes him as a "big boy / Doing a man’s work, though a child at heart." The chainsaw strayed over to his other hand and severed it, almost completely off. The boy held it up, probably dangling, and begged his sister to not let the doctor amputate it. However, that was wishful thinking, for "the hand was gone already." Then the doctor arrives and gives a general anesthetic, ether, presumably in preparation for amputating the hand. However, whether through the administration of the anesthesia, or more probably from profuse loss of blood, the boy dies. 

The use of the word "supper" is central in the poem. It is the word that causes the accident. It's fitting that it is a simple, humble word, rather than the more impressive synonym "dinner." The humble setting, a day of yard work at a country home, is consistent with this word. That the word is so mundane and such an "everyday" word creates irony in the poem. A simple, ordinary word created a horrific, extraordinary, completely unexpected result. This is what happens in accidental deaths. Often a completely normal, routine day changes radically into a momentous, life-altering moment when the accident occurs. Frost uses the simple word "supper" appropriately in the context to reflect both the ordinary setting and characters and to bring out the irony of the tragedy that grew from a normal day's activities.