Several people have been killed in a shooting Wednesday at a Swiss factory near Lucerne, authorities said, and at least four were critically injured. Police said the shooting took place at 9 a.m. at the wood factory plant called Kronospan in the town of Menznau. The factory employs 410 people, according to local media. No motive has been reported. There is no national gun registry in Switzerland, but it is estimated that up to one in three of the country’s 8 million residents own guns.