On October 3, 1979, a significant tornado hit without warning in Hartford County, CT devastating the town of Windsor Locks. This was one of the most destructive twisters to ever hit the state of Connecticut.
This F2 tornado hit during the late morning of September 6, 1973. Most of the damage was to roofs and there were garages that were destroyed. There were no injuries and no fatalities.
Per the SPC Database, there have been only 2 recorded F4 tornadoes in the state of Connecticut (since records began in 1950). One occurred Oct 3, 1979. There were 3 fatalities and 500 injuries. The second was part of this July 10, 1989 outbreak.