What Is The Correct Answers For This Question...

Hey all...Today i want to ask all of you 1 simple question...to all that have answers for this question,just send answers at my inbox on facebook http://www.facebook.com and search my inbox at this email:mieraamyrakzz@yahoo.com.After that,the correct answer will get a reward...hihi...What the reward is?  surprise...hihi...And the question is:

There was once a town where the train was the most popular mode of transport.People went north,south,east and west by train.It was fun on the train and everyone looked forward to going through the "MUST EXPERIENCE" tunnel on a hillside.The tunnel was long and had only one railroad.It was wide enoughfor only one train to pass through.It was dark,thrilling and mysterious.Strangely,one day,two trains went into the tunnel from the opposite directions.Each of the trains entered the tunnel at exactly nine o'clock.Four minutes later,each train came out at the opposite ends of the tunnel.Yet,everyone was safe and there was no head-on collosion.How was this possible?


So,who already have the answer can inbox me at my fb,okayy...The answer must in ENGLISH other language eventhough the answer is correct,will no be the winner..because i want the answer for this question in ENGLISH only...