CLARK, NJ - A Clark Department of Public Works employee was struck by a passing vehicle while working in front of the municipal building on Westfield Avenue yesterday.  The motorist did not stop. The accident occurred at about 2:00 pm.  The DPW worker suffered minor injury to his shoulder. There were no witnesses and the accident remains under investigation.  Anyone with information about the accident should contact the Clark Police Department, Traffic Division, by calling (732) 388-3434.