Short Story: "Sound of Thunder"

I thought that the short story "Sound of Thunder" was very interesting and not nearly as confusing as "All You Zombies" had been. The story had a lot of time travel in it including a 'Time Safari' company which took you, if you were willing, back in time to hunt various animals. Before every travel a man would go back in time to figure out which animal was going to die naturally and mark it with red paint. This way the hunters were taken back to right before the animal was killed and weren’t actually harming animals, just killing them right before they were going to die anyway. For example a dinosaur who was originally going to be crushed by a tree. On a trip, the hunters must walk on an anti-gravity metal path which I thought was pretty cool. Another intellectual excitement part of the story was the fact that while you are travelling back in time, you pass your future-selves heading back to the future without even realizing your passing yourself! Awesome, right? On a particular trip, a man named Eckels travels with a group of guys hunting dinosaurs. Travis, one of the trip leaders, explains to the group that it is important not to destroy any one tiny thing, like a mouse, because it could permanently damage the whole circle of life and cause some major changes for the future. The T-Rex the group is supposed to kill is then spotted. Everything becomes chaotic then and there are random shootings. This is when Eckels freaks out, steps off the path, and runs back to the time machine only to lay down in horror. The rest of the group ends up killing the T-Rex successfully and heads back to the time machine also. Eckels thinks he has done nothing wrong, only kicked up a pile of dirt, but ends up killing a small butterfly. When they get back to the future, everything seems okay accept for a few minor details, like the wrong desk, different wordings on a sign, and the wrong president re-elected. At the end of the story, Travis realizes the dead butterfly and raises a gun, Eckels closes his eyes, and there is a sound of thunder... a gunshot. Who was dead? Did Travis kill himself? Or did he shoot Eckels?