At least 310 people have now been reported dead in the series of powerful storms that ravaged several Southern states Tuesday and Wednesday. The tornadoes that caused most of the damage may have been among the largest and strongest ever recorded. "There's a pretty good chance some of these were a mile wide, on the ground for tens of miles and had wind speeds over 200 mph," said Harold Brooks of the National Severe Storms Laboratory in Norman, Okla. The National Weather Service Storm Prediction Center said they received 137 tornado reports on Wednesday, with 104 coming from Alabama and Mississippi. President Obama, who has pledged federal aid in the recovery, is scheduled to stop in Alabama today on his way to the Shuttle launch in Florida.