CLEVELAND—A lawyer for two Ohio counties told a federal jury on Monday at the start of a closely watched opioid trial that oversight failures by four large pharmacy operators including CVS Health Corp and Walmart Inc. helped fuel the deadly U.S. health crisis. Mark Lanier told a federal jury in Cleveland hearing on the first trial the pharmacy chains have faced in nationwide litigation over the epidemic, that the companies bore responsibility for drug abuse in the counties of Lake and Trumbull. The other defendant pharmacy chains are run by Walgreens Boots Alliance Inc. and Giant Eagle Inc. The counties contend they failed to ensure prescriptions were valid, causing an oversupply of pills, overdoses, and deaths. “They’re known as the last line of defense,” Lanier said in his opening statement. “These are the people who are putting the pills on the streets. They have to provide effective controls.” Opening statements …