The Village of Caseyville lost a police cruiser in the line of duty Monday when an alleged intoxicated driver crashed into it at a sobriety checkpoint.  According to police reports, the officer who drove the patrol car was checking for drunken drivers about 1:30 AM Monday, when a motorist failed to stop and smashed into the police vehicle.  Neither the officer nor the motorist was injured in the crash.  But both cars suffered extensive damage, police said.  The motorist was charged with suspicion of DUI by Illinois State Police.  They were operating the checkpoint along with Caseyville officers as part of the Illinois Department of Transportation’s sustained traffic enforcement program.