 I was like, a car must have went through there. It's not yet clear if the four dead were customers or employees. Nine others, including the driver, were taken to hospitals. Maybe everybody's trying to escape the heat. Whatever the reason, it's becoming an extremely busy travel weekend ahead of the July 4th holiday. The TSA expects 3 million people to pass through airline security checkpoints any day now. When that happens, it would mark the busiest airline travel day ever.