People are plopped down in the middle of huge piles of luggage, cell phones in hand, still looking for a ticket home and according to some stranded passengers, the airlines aren't making any new friends.
"I've been here for about two days," said passenger Micah Mitlyng.
Mitling was just passing through on his way from Alaska to New Zealand.
But with the wreckage of Saturday's Asiana Flight 214 crash still blocking one of the runways, he's gotten an unexpected stay in San Francisco.
"Well last night I slept in the hotel, but at the airport the other night. And I'll probably hang out here for the rest of the day," said Mitlyng.
He's not alone.
Chris Marchewka missed his connection to Hong Kong by 30 minutes. Now, he and his wife are stuck without their children.
"I've been out. First time ever we leave them alone, so five days without them it's, you know, it's pretty big," he said.
Like so many other stranded passengers, Marchewka and his wife were flying on United Airlines. United has had to deal two-thirds of the more than 300 canceled flights at SFO.
While other airlines diverted many passengers to Oakland and San Jose, SFO is a hub for United and they just don't have enough gates at the other airports to handle all those planes.
Vikki Jones was one of the lucky ones. Her flight was diverted to Oakland. But then she found out her rental car reservation was no good there.
"Got to Oakland and they said we could take a shuttle over to the airport, so we got the shuttle that took us to the Coliseum; which took us to a train station. We had to take the train and now we're here. Two hours it took us to get from Oakland to here," she said.
With the wreckage likely to continue blocking the runway for days, American Airlines says it's flying bigger planes -- trying to get more passengers where they need to go with a limited number of flights.