text:  The TSA expecting more than 3 million people to go through U.S. airports security checkpoints today alone. That would be an all-time record. Under 100 flights have been canceled today. That's actually pretty good for a major getaway day. They're peppered around the country. No one U.S. airport is getting slammed. And many are because of problems in London. Flights that are coming from or heading to London. United has the most canceled flights and it only has 14 flights canceled. That's less than 1% of United's schedule. ABC's Alex Stone.