2010 was a record year for tornadoes in Minnesota. Over 100 twister crashed through the state, and almost half of which occurred on one day. June 17, 2010 saw 48 confirmed tornadoes hit Minnesota. This was the most tornadoes to happen in a day in the state. The old record was 27 in one day on June 16, 1992.
The June 17th outbreak caused three deaths and 46 injuries in Minnesota. The last time more than one person was killed by tornadoes during a single day was March 29, 1998. A complete summary of every 2010 tornado can be found here.