Red Hot Chili Peppers lead singer Anthony Kiedis was rushed to hospital in an ambulance on Saturday (14.05.16).
The band were forced to cancel their KROQ Weenie Roast headlining performance just hours before they were due to take to the stage after Anthony suffered "extreme stomach pains", Billboard reports.
A tweet on KROQ's page said: "Unfortunately due to illness the @ChiliPeppers were forced to cancel their set tonight at #WeenieRoast. More details to come."
Bassist Flea took to the stage with his bandmates at the Irvine Meadows Amphitheatre in Irvine, California to explain the situation.
He said: "We are devastated about it. We live to rock, we live to f**king kick deep into the depths of our hearts and rock, but unfortunately there's a medical thing that happened and we need to deal with it."
Anthony, 53, battled drug addiction in the past and also nearly suffered organ failure due to kidney disease but those close to him rushed to assure fans that he is "healthy".
Nancy Mack, the wife of Peppers drummer Chad Smith, tweeted: "Even super healthy guys get sick."
And photographer David Mushegain, who has worked with Anthony, wrote on Instagram: ".. a lot of chili peppers fans r messaging me so just want to pass on that everything is going to be ok ...."
Weezer replaced RHCP to close the show which also featured Panic! at the Disco, Empire of the Sun, Garbage, Lumineers, Fitz and the Tantrums and Miike Snow and a surprise Blink-182 set.
Tagged in Anthony Kiedis