The Petaluma man killed in a motorcycle crash Monday morning is being identified as Michael Grossman. The Marin County Sheriff says the 46-year-old was involved in a three-vehicle crash on southbound 101, just south of San Antonio Road. CHP investigators say Grossman came upon slowing traffic and crashed into the back of a van, lost control of the bike, and collided with another vehicle in the right lane. The southbound lanes were blocked at the scene for about two-and-a-half hours.