An autopsy for an Obama for America campaign staffer who died after collapsing in the Chicago headquarters was inconclusive Saturday. Alex Okrent, 29, collapsed at the Obama headquarters in the Prudential Building on Friday, authorities said. Paramedics gave him emergency treatment before taking him to Northwestern Memorial Hospital, where he was pronounced dead at 11:45 a.m. on Friday, according to the Cook County Medical Examiner’s office. The autopsy requires further studies before a cause of death can be determined, according to the medical examiner’s office.