Who wrote a short story "A Sound of Thunder"?

"A Sound of Thunder" is a science fiction short story by American writer Ray Bradbury, first published in Collier's magazine in the June 28, 1952, issue and later in Bradbury's collection "The Golden Apples of the Sun" in 1953.

There are five characters in the story viz a rich businessman and huner, Eckels, Travis (the guide), Lesperance, and other two hunters Billings and Karmer.

The Safari is for hunting a huge dinosaur T-Rex. When they are in Time Machines, he tells if a rat is killed eventually it will destroy fox, lion to civilization. Actually, they can kill animals that are going to die naturally.

Eckels gets too nervous because it's too big, it goes off the track, so Travis and the others kill the animal. Travis warns Eckels that he didn't obey the rules and his order, plus Travis gets furious when he sees Eckels' muddy boots.

When they return they notice that the alphabets on the office signs are different. Finding a dead butterfly on the sole of his boot, Eckels asks Travis to bring him back to the past so he can repair the damage. Travis refuses and says that's impossible. In the end, Travis fires the rifle at him, but it's unclear who fired. He is supposed to kill Eckels.

Ray Douglas Bradbury (August 22, 1920 – June 5, 2012) was an American author and screenwriter. One of the most celebrated 20th-century American writers, he worked in a variety of modes, including fantasy, science fiction, horror, mystery, and realistic fiction.