A 46-year-old Pleasant Hill man was killed Thursday afternoon around 4:30 while traveling west on highway 70 near Pleasant Hill.  According to the THP report, David Heiden was driving west on 70 in a passenger car when an oncoming pick-up truck crossed the center line and hit the Heiden vehicle head-on.  The driver of the East bound vehicle, 23-year-old Joseph Walters of Sparta, was not injured in the crash.  A passenger in Walters pick-up, 46 year-old Karen Siddons, was injured in the crash with non-life threatening injuries.  The THP report indicates heavy rain during the time of the accident may have been a contributing factor in the crash but that charges are pending.