A 19-year-old man crashed into the guardrail of a bridge after losing control of his motorcycle on a mountain road in Chiayi County yesterday, and plunged 15 meters into a boulder-strewn stream bed below. Fortunately, the man landed on a discarded mattress, and survived the fall with only minor injuries, including a busted knee, and a mild concussion. At around 5:00pm, Mr Cheng (程 ), 19, was riding a heavy motorcycle on Provincial Highway 3 (Inner Mountain Highway), in Chiayi