Many in Joplin ignored first tornado warnings, National Weather Service says

Tuesday, September 20, 2011 | 2:41 p.m. CDT; updated 3:09 p.m. CDT, Tuesday, September 20, 2011

KANSAS CITY — Many Joplin residents either ignored or were slow to react to the first warning sirens about a massive and deadly tornado this spring, partially because of years of false alarms, the government said Tuesday.