Flywheels are typically made of steel and rotate on conventional bearings; these are generally limited to a revolution rate of a few thousand RPM. Some modern flywheels are made of carbon fiber materials and employ magnetic bearings, enabling them to revolve at speeds up to 60,000 RPM (1 kHz). Carbon-composite flywheel batteries have recently been manufactured and are proving to be viable in real-world tests on mainstream cars.
1925: The Tri-State Tornado. Indiana was one of three Midwest states in the path of the deadliest tornado in American history. On March 18, 1925, the Tri-State Tornado traveled a record 219 miles on the ground from Missouri through Illinois and into Indiana, where it struck Posey, Gibson and Pike counties.
Geneva-area historical tornado activity is near Indiana state average. It is 83% greater than the overall U.S. average. On 11/10/2002, a category F4 (max. wind speeds 207-260 mph) tornado 16.4 miles away from the Geneva town center killed 4 people and injured 17 people and caused $30 million in damages.