Alva Review-Courier -

When the warning sounded shortly before midnight that a tornado could be approaching, the clock turned into a stopwatch for staff members working the night shift at a behavioral health center at a Sioux Falls hospital.

"We had 10 minutes to wake up 102 residents, get them to the center of the building," said David Flicek, the president and CEO of Avera McKennan Hospital and University Health Center in South Dakota's largest city. "And all are safe and sound."

Although a significant tornado had not struck Sioux Falls for 25 years, the Avera Health System hospitals have kept up regular preparedn...