ROSEVILLE, Calif. -- Evacuations were ordered at the Westfield Galleria at Roseville Monday night because a "flash mob" by the Sacramento Choral Society brought an overcrowding concern.
Fire officials said there were several thousand people in the mall.
Roseville Fire Battalion Chief Peter Mashnat said some people inside claimed the floor was shifting and moving and that they heard cracks and pops in the foundation.
He said officials wanted to evacuate people as quickly as possible as a precaution.
The Sacramento Choral Society & Orchestra said on its website that "Hallelujah! A Spontaneous Celebration of Great Music, Community, the Season, and the reopening of the Westfield Galleria at Roseville," was planned.
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A "flash mob" is a group of people who get together to do an activity at a moment's notice and then disperse. The event is usually organized online and notifications are sent by e-mail or text.
The group took its event outside after the mall was evacuated.
The Roseville Fire Department said the mall's "anchor" stores were never closed. Westfield officials said the mall will open as usual on Tuesday.
Structural engineers went to the mall to check for any damage, Mashnat said.
No injuries were reported as of Monday night.
Traffic was jammed as people tried to leave the area.
Westfield later apologized to shoppers in a statement for the inconvenience.
"The enthusiasm for the Halleluiah event tonight was far greater than anticipated by organizers. Out of an abundance of caution, the center was evacuated. We apologize for this inconvenience. However, the department stores: Sears, Macy's, Nordstrom and JCPenney remain open per their holiday hours. Once cleared by the authorities, the center will resume normal operations," Westfield said in a statement.
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