MANKATO, Minn. (AP) -- Authorities say a quarry blast - not an earthquake -
apparently caused the ground to shake in Mankato.

Tremors were felt throughout the city about 11 a.m. Tuesday. The Blue Earth
County Sheriff's Office says the shaking apparently came from a blast at
Jefferson Quarry.

Mike Maurer, the county's emergency management director, says there were no
reports of major damage.

The city of Mankato said in a news release a vibration felt through most of the
city may have been due to weather, with overpressure causing a ``pressure

Reports say the dispatch center was overwhelmed with 911 calls.

Some residents said they felt like their homes were going to collapse.

The explosion shook the historic courthouse, temporarily halting a county board