Police want residents of the Salem area to check the undercarriage of their cars for signs of pipe bombs like the four discovered around Salem and Dallas on Thursday. There may be more bombs out there, police said. Two of the bombs were found attached to cars with wires and other two probably were attached to cars, too, but fell off and were found on roads, Salem police said this afternoon. The drivers of the cars may never have been aware of the bombs. Police said they considered the episode "a very serious situation." All the of the devices could...