One Earth, Wind & Fire member has suffered from a medical crisis.

The band announced that it was “unable to perform” its Aug. 6 San Fransciso concert at Chase Center as scheduled “due to a medical emergency involving a member of our band.”

“As a result, tonight’s show with Lionel Richie will be rescheduled, with a new date to be announced soon,” the band wrote in an Instagram post just around showtime, at 7:30 p.m. PST. “Ticket holders should retain their tickets, which will be honored for the new date, or refunds will be available at the point of purchase. We sincerely apologize for the unexpected change and appreciate everyone’s understanding.”

The band did not announce which band member suffered the emergency or what the medical issue was. USA TODAY has reached out to Earth, Wind & Fire’s reps for comment.

The postponed performance comes a month after Lionel Richie postponed shows after he appeared to suffer a dizzy spell onstage during the opening concert of his Sing a Song All Night Long Tour with the legendary band.

The fellow R&B icon performed his upbeat hit “Dancing on the Ceiling” while sitting on a step on stage, per the Minnesota Star Tribune, which he admitted he’d never done before. Shortly after, just over halfway through his set, the 77-year-old singer announced an “intermission” but didn’t return. A band member later announced he “wasn’t feeling well,” while Earth, Wind & Fire drummer John Paris told the outlet the singer was “a little dehydrated.”

“Under advisement by doctors to rest and return to full health, Lionel Richie has postponed his next two shows,” Live Nation Chicago later announced.

The Grammy-winning singer made his lively return in Pittsburgh in better spirits. The concerts in Chicago and Columbus, Ohio, were rescheduled for Sept. 30 and Oct. 2, respectively.