From the National Weather Service's St Louis office: http://www.crh.noaa.gov/lsx/?n=04_22_2011
SURVEY TEAM RATE DAMAGE AT LAMBERT ST. LOUIS INT'L AIRPORT AS EF 2
The National Weather Service damage survey team at Lambert St. Louis International Airport has found EF-2 damage. Nearly 80% of the windows in the easternmost part of the terminal were blown out...and the roof was torn off of Terminal C. EF-2 damage indicates winds of 111 to 135 mph.
INITIAL DAMAGE SURVEY INDICATES EF 4 DAMAGE IN NORTH ST LOUIS COUNTY
The National Weather Service damage survey team in north St Louis county has found EF-4 damage in the Bridgeton area...near old St Charles Rock Road and Harmon Estates. EF-4 damage indicates winds of 166 to 200 mph.