Disneyland's Toontown reopened Tuesday night after a loud explosion prompted authorities to close it for hours as a precaution.
The explosion was caused by dry ice in a water bottle, according to bomb squad and Anaheim Police Department officials. No injuries were reported.
"At this point, we don't know it was on purpose or by accident or accidently thrown away," said Sgt. Bob Dunn, with the Anaheim Police Department. "We are looking at all aspects."
Local news from across Southern California
Dunn added that people too often mistakenly try to enclose dry ice. Investigators plan to review surveillance video to determine who placed the item in the trash bin.
"We do respond to these quite a bit, so we know what to look for," he said.
Disneyland issued this statement late Tuesday:
"This afternoon, a small bang was heard in a trash can at Mickey's Toontown (and) in an abundance of caution, we evacuated Toontown to allow local authorities the opportunity to investigate," Disney spokeswoman Suzi Brown said.
The exact time of the explosion wasn't clear, Dunn said.
However, some Twitter users mentioned the incident at about 5:30 p.m.
"Something went BOOM in Toontown at Disneyland and now they're evacuating," wrote @theallenwolf at 5:33 p.m.
Minutes later, @SurelyShawna tweeted: "Was sitting in Toontown at Disneyland and something exploded in the trash can. I felt the sound waves of it and Toontown is closed."
Allen Wolf was writing on his computer near Toontown's City Hall -- about 20 feet away from the explosion -- when he heard a "loud boom."
He said there was no panic among parkgoers (pictured below), but there was a "tenseness."
"It sounded like a gun shot, but it was so out of place because we're in Toontown that most of (us) didn't know what to think," Wolf said. "When no one panicked and there was no indication of what happened," we continued doing what we were doing.
Soon after, Disneyland employees began escorting crowds from the area.
"They don't really tell you anything," Wolf recalled. "They just stay smiley and they say, 'We don't know what's going on but we need you to evacuate.'"