The crowd began gathering in front of Boston's old red brick Touraine Hotel before anyone inside knew that someone had climbed out a ninth-floor window and was teetering on a ledge high above Boylston Street. The Touraine faces Boston Common like a stage set; within minutes, traffic was inexorably jammed and thousands were jostling together in the afternoon drizzle, heads back, faces eager, eyes fixed on the improbable figure high above them.
The ledge-walker was a teen-age boy in a wine red shirt and khaki pants. He dropped his jacket. The crowd rumbled as it fell. "Jump!" bawled a voice...