KALAMAZOO -- Police in Kalamazoo are investigating a meth lab explosion.  Around 8 p.m. Wednesday, officers were dispatched to the Forty Winks Motel in the 2600-block of Douglas Avenue.  Kalamazoo Township police officers found evidence of an explosion from what appeared to be the manufacture of meth.  Witnesses say they saw two people leaving the scene in a gray SUV.  No injuries were reported and they're still investigating.  They ask that anyone with information get in touch with police.