An Oklahoma inmate whose execution was halted Tuesday because the delivery of a new drug combination was botched died of a heart attack, the head of the state Department of Corrections said. Director Robert Patton said inmate Clayton Lockett died Tuesday after all three drugs were administered. Patton halted Lockett's execution about 20 minutes after the first drug was administered. He said there had been vein failure. The execution began at 6:23 p.m. when officials began administering the first drug, and a doctor declared Lockett to be unconscious at 6:33 p.m. About three minutes later, though, Lockett began breathing heavily,...