Arianne never expected Magnus would foolishly risk his life for her, even when she rejected him. But to label him as a fool, does she have the right? No. She doesn't because she's also one herself. Even knowing that the hospital was the burial place for most survivors, she also chose to charge in for Dante. They're both fools. Fools for love.
As she broods over this matter, the zombies began to gather under the gap of the destroyed ceiling on the 12th floor. The noise produced by the sudden collapse, attracted the zombies from the 10th floor to the 13th floor. They rushed towards the source of the noise and crazily began to wave their claws.
Due to overcrowding, they were pressed together like sardines in a can and some zombies managed to climb over the rotten bodies of the others, and it didn't take long for one of them to enter the vent.