Explosion reported at Wal-Mart in a dumpster .At 3:49 pm city police requested the VWFD to investigate the contents of three dumpsters located in the west parking lot of Wal-Mart's parking lot. A witness told police that an explosion with smoke poured out of a dumpster when the lid flew open after the explosion. Fire department personnel cut the padlocks off all three dumpsters and found no evidence of an explosion. However four hypodermic needles were found in one of them. They were collected by officers and put in proper disposal containers.