Look what was inside:
From http://www.sfgate.com/news/article/...d-in-crash-at-Bay-12400452.php#photo-14639595 :
From http://www.sfgate.com/news/article/...d-in-crash-at-Bay-12400452.php#photo-14639595 :
Williams said the truck was filled with what he described as lighting or sound equipment. After hitting the five other vehicles, it plowed through the barrier in front of the toll booth for Lane 15, on the north side of the plaza, and smashed into the booth itself.