*Being fired was technically the "death" of Willy as a salesman, and his actual death was so soon after the loss of his job that Miller might have meant that the death in the title was in fact Willy being fired.
Willy Loman had a road job. He was constantly on the road in order to sell merchandise. The fact that he committed suicide and died by way of a car is much more appropriate than gas poisoning by inhaling the fumes from the water heater. Besides, Biff had taken off the hose to the water heater, effectively canceling out that as an option for Willy to try and kill himself. It seems that he didn't much of a choice if looked at in that way.
Overall, Willy's death seems to be rather anti-climatic and unnecessary. For Linda, it was a shock, considering they were almost finished with all their troubles and they were finally working on getting along with Biff and Happy. They seemed to be coming together as a family when Willy decides to die. If the situation is looked at with an absence of emotion, then it could be said that Willy's death did a lot of good. His family would no longer be submitted to his lies, Charley would no longer have to pay out fifty dollars a week, and Biff and Willy would of course no longer be able to fight. No longer would any tension between the members of the Loman family in regards to Willy exist, but they did lose a vital person in all their lives. The effect is devastating even when the member of a family dies that is hated or despised. Willy was simply "not well-liked." His family did indeed love him and his death was hard on them all. Linda is now technically on her own as well. Who will support her now? Linda gave the majority of her life to support Willy Loman, now let’s hope the insurance money from his death will be enough to support her in his absence.