Teamwork at the ruins (Patreon)

Umi and Sunny (requester's OCs) explored a sunken subway ruins together. Sunny is carrying a rebreather with her as Umi prefers to take the tradition freediving  with her sport clothes.

After a bit of exploration together, they find an alternative way out, blocked by the ruined celling of the subway. Umi is able to take care of the path so that Sunny can open the door for them, which seemed to be locked.

Can they find their way out of the subway in time?