A 77-year-old man was killed Monday night after he was inadvertently knocked from a platform at Keio Line's Shinjuku Station by a drunken man and hit by a train, police said Tuesday.

The drunken man had stumbled on the platform and bumped into a line of people waiting for a train, creating a domino effect and causing the man at the front of the line to fall onto the tracks at around 8:35 p.m., the police said.

The victim has been identified as Masaya Sato from the Tokyo suburb of Tama. He was president of Hokkaido-based Seisa University, a professor emeritus at Tokyo's Keio University and the son of novelist Haruo Sato.

The police arrested Yukinori Fujii, a 42-year-old part-time worker from the suburb of Hino, who had been sitting on the platform waiting for a train before allegedly standing up and bumping into the commuters.

Fujii was initially arrested on suspicion of negligence resulting in Sato's injury, but after Sato was confirmed dead the charge was changed to negligence resulting in death.

A police official quoted Fujii as saying, "I drank beer and 'chuhai.' When I stood up, I felt dizzy and lost my balance."