CHICAGO (AP) _ A section of floor collapsed under the weight of sand placed there for a flower and garden show at the Navy Pier entertainment district Friday.

Authorities don't believe anyone was injured but can't be certain until the huge mound of sand is removed.

The 20- by 60-foot section of floor collapsed about 4 p.m., burying a parking lot and damaging pipes, electrical and phone lines and at least one car.

The collapse caused a tremor through the popular tourist destination, and one nearby restaurant had to close for business.

Workers were hauling away the sand Friday night.