The good news is that the first responders of this show are brave and resourceful enough that the people of Los Angeles are in the best hands they could be in post-tsunami; the bad news is that Buck and Christopher were at the pier when the tsunami hit, and Buck lost track of Christopher when the water began to rush back out to sea.
9-1-1 devastated the Santa Monica Pier in the second episode of Season 3 when the long-awaited tsunami finally reached shore.
Additionally, Ronda Rousey made her 9-1-1 debut, and her character’s fate was left in question too.