When did the story happen ?

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TRAGIC ACCIDENT

    When I was walking home from school yesterday, I saw an accident. A car hit a motorcycle from behind. The driver couldn't control his car because he drove very fast.

    The car didn't stop after the accident. It even ran faster and disappeared. The traffic was not so busy. No one came to help the motorcycle's rider. He was injured badly. I was so scared at that time.

    Then I called the police and tried to find help for the victim. Not long after that the police came. The police asked me several questions. I told them what happened.

    Then I saw an ambulance took the victim to the near hospital. After that I went home because it was already dark. It was really tragic.

When did the story happen ?