They found Mr. Yang later on, but his daughter wasn't with him any longer.
Calvin also only appeared when Treyton went to his university to look for him.
The most unfortunate person among them would be Nathan.
In the novel, when Treyton went to his clinic, no one was there, and the place was full of blood. It was presumed that he was eaten by zombies.
He let Treyton invite all of them here because he wanted them all to survive and, of course, for them to at least have a smooth beginning because they were all the people he had already met.
Especially Nathan, who also died at the beginning.
Luciel had been getting along with him when he came to check on Treyton's wounds for the past two weeks.
They even played games together sometimes, so he wanted to give him a chance to survive this time.
They all stayed in the living room to wait for Nina to come back.