Sunday night, several British Airways passengers arrived at BWI Airport, just one day after deadly attacks in London.
Kelly Tenbrink, of Washington D.C. was there on vacation.
"A lot of thoughts are going through your mind," she says, "a lot of 'What If's.'"
Tenbrink says she walked over the London Bridge with thousands of other tourists just days before a van struck pedestrians on Saturday night.
"Just thinking about that, and thinking about the possibility that we were there, was very scary," she says.
Across the country, other travelers are departing for London. They're unsure about what to expect when they get there.
"We've already bought the tickets for everything and we're staying right in the city," says Tiffany Horton, who is flying out of Los Angeles, "You can't stop living. You just have to go and hope for the best."
Whether coming or going, all of the passengers have the same groups on their mind: the victims and their families.
"I pray for all the families who were victimized from it," Tenbrink said.