The final KROQ Weenie Roast at Irvine Meadows came to an unexpected and early end on Saturday when headliners Red Hot Chili Peppers were unable to take the stage due to an unspecified medical emergency involving singer Anthony Kiedis.

Empire of the Sun had just finished its set about 9:30 p.m. when KROQ DJs Kevin Ryder and Stryker came on stage, and then brought out all the members of the Red Hot Chili Peppers – except for Kiedis.

Bassist Flea told the crowd that as much as they had looked forward to playing the show, and as bad as they felt about not being able to, there was no way to do so.

“Unfortunately our singer is on his way to the hospital and we are unable to play tonight,” Flea told the crowd, a great many of whom had shown up wearing Chili Peppers shirts.

Update: Red Hot Chili Peppers spokesman Brian Bumbery told the Associated Press on Sunday that Kiedis was suffering from intestinal flu and is expected to make a complete recovery.

Backstage, leading up to the announcement, there was a sense of chaos as the Chili Peppers and musicians from other acts conferred with production staff. No one would say anything further about Kiedis or what had happened.

Flea and drummer Chad Smith had watched Blink-182 – the surprise guest this year – from the side of the stage, with Smith particularly animated as he studied drummer Travis Barker and sang along.

But as Empire of the Sun played after Blink-182, members of Red Hot Chili Peppers, as well as KROQ DJs and members of No Doubt, were seen running toward the artists’ trailers.

When Weezer wrapped up what became its unplanned headlining set, disappointed fans in Red Hot Chili Peppers T-shirts slowly filed out of the amphitheater.

Heather Collins of Buena Park and Jade Voigt of La Habra had scored front row seats to see the band live for the first time.

“I’ve loved them for as long as I can remember,” Voigt said. “I think my first tape in fourth grade was ‘Under The Bridge.'”

Both looked dejected but said they didn’t blame the band or KROQ.

“I’m disappointed but I mostly hope he’s OK,” Voigt said.

Alex Betancourt drove all the way from Palmdale with his daughter Kathleen and niece Isabel Kollar. He’d seen the band before but this would have been the first for the girls, and a high school graduation present for Kathleen.

“We love all their songs,” Betancourt said.

“We were singing them all day while we were waiting in line,” Kathleen said.

There has been no official word on why Kiedis was rushed to the hospital, though some reports say he was having stomach pains.