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"It looked like he did a massive face plant after his encore and pretty much didn't get up," audience member Dan Bateman told the Telegraph. "We were told to leave the premises ... No one really wanted to leave because everyone was anxious to know if he survived the fall. Everyone was pretty horrified."
Jimmy is now in stable condition and is undergoing observation, a hospital representative tells ABC News Radio.
Wednesday's show was the last of the 'Margaritaville' singer's three-night run at the Sydney Opera House. It was his first trip Down Under in 20 years. He's scheduled to perform in Auckland, New Zealand this Saturday. There's no word yet on whether that show will have to be rescheduled.