 Complete the following phrase:  Despite not many tornadoes being documented, 1953 was an extremely deadly season and set the record for most tornadoes recorded in the U.S. in a single year at the time. The first six months of the year generated several large outbreaks and outbreak sequences that killed over 400 people. Activity abruptly slowed after that before another outbreak sequence in early December killed 49. Many of fatalities were caused by the unusually large number of violent tornadoes that were recorded that year. This included five F5 tornadoes, the first F5 tornadoes recorded in the US tornado database created in 1950. In all, there were 523 tornado-related fatalities in the US alone in 1953, the most since 1925. This high a death toll would not be repeated until 2011. There were 5,131 injuries recorded throughout the year as well. 1953 is also the only year since 1950 to have three tornadoes kill over 90 people and to have two tornadoes kill over 110. On a positive note, major changes were made to improve both the warning and radar systems. These changes were successful and since 1953, only one tornado, the 