CHICAGO (CBS) — Although they are rare, twisters with the kind of force that flattened Moore, Okla., have hit the Chicago area in the past, and have been extremely deadly.
There have been eight EF-4/5 tornadoes to hit the Chicago area between 1950-2010, the latest official data available from the State Climatologist Office For Illinois. (Unofficially, we could find no evidence of a tornado of that size in the past 2.5 years.)
The deadliest tornado ever in Chicago happened in 1967, when 33 were killed by an EF-4 twister that hit Palos Hills and Oak Lawn.
The 1960s were also the deadliest decade for tornadoes with nearly 70 people killed.
While one tornado killed 29 people in Plainfield in 1990, improvements in advanced warning have clearly saved lives. Taking away the Plainfield tragedy, about 10 people have died in the past 33 years.
Some significant tornadoes to hit the Chicago area:
March 28, 1920: An EF-4 tornado traveled over a 53 mile path, starting in Channahon, moving northeast to Wilmette and over Lake Michigan. The worst damage was in Maywood and Melrose Park. A total of 20 people were killed and 300 injured.
March 4, 1961: A rare tornado hits Chicago. And EF-2 ripped through the South Side—starting at 91st and Western and traveling to 68th Street and Lake Michigan. One person was killed, 115 hurt. The storm caused $7 million in damage.
April 11, 1965: An EF-4 hit McHenry, Crystal Lake and Wauconda, killing six and injuring 75.
April 21, 1967: A massive EF-4 storm cut a 28 mile path from Cherry Valley, to Belvidere and Woodstock. A total of 24 people were killed and 500 injured. Thirteen were killed and 300 injured as 12 buses were tossed around Belvidere High School at dismissal time.
April 21, 1967: A violent EF-4 tornado formed in Palos Hills in Cook County and traveled through Oak Lawn and the South Side of Chicago. A total of 33 people died, and 500 people were injured by this 200 yard wide tornado that traveled 16 miles and caused over $50 million in damage.
June 13, 1976: An EF-4 tornado hit Lemont and traveled for eight miles, leaving $13 million in damage. Two people were killed and 23 injured.
August 28, 1990: A total of 29 people died and 353 people were injured when an EF-5 tornado pulverized Plainfield. It is believed to be the only EF5 tornado to strike in Chicago area.
April 20, 2004: A tornado destroyed more than half of downtown Utica. The EF-3 tornado killed nine people, including eight who died in the basement of the Milestone Bar.
Other facts about tornadoes in Chicagoland:
The most common month for tornadoes: April (There has been a tornado in January!)
The most common hour of day for tornadoes: 5 p.m. This is by far the most common hour for a tornado to occur. Tornadoes rarely happen at night. The most common window for tornadoes is between 2 p.m. and 7 p.m.
The most common strength of a tornado: EF-2
Number of tornadoes to hit Chicago proper since 1885: 3
Number of confirmed tornadoes, by county between 1950-2010:
The EF Scale:
1: 86-110 mph
2: 111-135 mph
3: 136-165 mph
4: 166-200 mph
5: Over 200 mph
Source: State Climatologist Office For Illinois/National Weather Service