Dragon Head volume 1 manga

Teru Aoki is returning with his classmates from a school trip when he sees a weird beam of light in the distance. The train passes into a tunnel just before an earthquake hits. Teru manages to survive, but everyone else in his car is killed. When he escapes the car to explore, he finds two other survivors — Ako Seto, an unconscious girl, and Nobuo Takahashi, who is rapidly degenerating into insanity and claiming that he sees 'something' in the darkness in the tunnel. Both ends of the tunnel are also blocked, and the whole thing is getting steadily hotter for no apparent reason.