Three former lead paint makers were found liable...for poisoning thousands of children in Rhode Island in a landmark lawsuit that could trigger a wave of litigation against the industry. The verdict...could force the companies to pay millions of dollars in clean-up costs and mitigation...The companies found liable are Sherwin-Williams Co. , NL Industries Inc. and Millennium Holdings LLC [part of Lyondell]. A fourth defendant, Atlantic Richfield [now part of BP], was not found responsible...The cities of Chicago, Milwaukee, San Francisco and St. Louis have also filed suits against former lead paint makers.