As London authorities tighten their search for anyone affiliated with Saturday night's attack, the incident is front and center on the minds of travelers.

"It's quite emotional, actually," said Doug Lacoss, who takes the London Bridge to get to work every morning.

Both Lacoss and his wife, Coralie, are Americans, but have called London home for the past 2 decades.

Coralie said her friends were sightseeing right before the attack happened.

"They had been there just hours before with their children. They're English so they had gone sight seeing and they had been there walking around, and you just think had it been just one more hour that they had decided to be there, it could have been them," said Lacoss.

Saturday's incident marks three terror attacks in the U.K. within the last three months.

Most recently, 22 people were killed, and 100 more injured when a bomb went off during an Ariana Grande concert in Manchester.

Doug, on the other hand, hopes attacks don't stop people from going about their daily lives.

"It's going to happen or it's not, and you can't really change just because something like this happens, it's still quite rare," he said.