Barry is attacked by the shark-man and is saved by Harrison Wells when Patty's gun is insufficient for the job in episode #204 "The Fury of Firestorm". The police fight against the meta-humans under Zoom's control in episode #222 "Invincible".
Cisco has a vision of birds crashing into the ground on Earth-2 in episode #222 "Invincible".
Cisco travels to Earth-19 where Cynthia Reynolds is reporting on the success of her latest assignment and tries to get her to return to help on Earth-1 in episode #314 "Attack on Central City".
Diggle follows Moira to a covert meeting with Malcolm and overhears part of it in episode #113 "Betrayal".
Laurel rants about her father spying on her to Tommy who gets mad about her talking to The Vigilante in episode #113 "Betrayal".
Diggle finds one of the virus carriers at a downtown plaza who is then taken out by Thea in episode #323 "My Name Is Oliver Queen".
Oliver meets Merlyn in a downtown square in episode #304 "The Magician".
Kendra and Carter part ways with the group and Oliver and his crew get ready to head back to Star City in episode #408 "Legends of Yesterday".
Marina walks to catch a cab while talking with a west coast hedge witch about their god problem in episode 2x02 "Hotel Spa Potions".
Rip arrives with a few of the Legends shortly after a younger version of himself dropped of Henry Heywood only to find he has already disappeared into the crowds in episode 2x14 "Moonshot".
Kara tries to stop Lillian and Metallo from fleeing but is forced to save a bunch of bystanders in episode 2x12 "Luthors".
A big piece of debris crushes a steel drum band in the Wayne Security video in episode #101 "Wayne or Lose".