New Delhi, Aug. 7 -- 30 p.m. start time for an evening of Earth, Wind & Fire and Lionel Richie. At 7:20 p.m., a statement from the band dissolved the night entirely. A medical emergency involving a member of Earth, Wind & Fire had forced the postponement of the concert, without warning and without detail.

"We are unable to perform as scheduled tonight at Chase Center in San Francisco due to a medical emergency involving a member of our band," the group said in a statement. The announcement did not name the affected member, describe the nature of the emergency, or disclose the member's condition. No rescheduled date accompanied the statement.

Arena staff directed concertgoers who had already entered to exit the building. Fans still arriv...