Three people were injured Friday night when panicked audience members "self-evacuated" during a performance of the musical "Hamilton" in San Francisco, police said.
A woman in the audience had a medical emergency during the scene in which the title character, Founding Father Alexander Hamilton, is shot on stage, said Joseph Tomlinson, public information officer for the San Francisco police.
Audience members mistakenly thought there was a real-life shooting and rushed the exits, he said.
CNN affiliate KPIX reported the someone in the audience shouted, "Gun!"
Police told reporter Shirin Rajaee -- who was in the audience -- that a woman was having a heart attack and someone in the theater thought she had been shot. In the chaos, some people jumped into police patrol cars.
The woman and three injured people were taken to local hospitals, police tweeted. One of the three people injured had a broken leg. The woman who suffered the medical emergency was taken to a hospital and reported in critical condition.
Cast members had to evacuate the Orpheum Theatre as well. An Instagram video shows them returning inside from the street.
The theater's explanation on Twitter did not sit well with some who attended.
"During a medical event at the SHN Orpheum Theatre this evening an audience member activated the theater's fire pull station," the theater said. "The audience and cast followed the life/safety system's automatic announcement and exited the theater."
Patron Laura Lasnier described "mass chaos" in a tweet.
"I was in the balcony with my 6 and 9 year old. There was absolutely NO announcement. There was mass chaos and absolutely no support and direction from SHN staff. Extremely disappointed in how the event was handled," she tweeted.
The performance of the popular Tony Award-winning show did not continue.
Tickets cost up to $686 officially and are offered online for hundreds of dollars more.