What started out as a late-night quarrel between colleagues at Tokyo Station turned into a deadly accident, leading to the arrest of a 54-year-old systems engineer, police said Sunday.

Yasushi Fukunishi is being held on suspicion of fatally hitting the left eye of his colleague, Yoshiya Takishima, 55, with an umbrella near the station's Yaesu South Exit shortly before midnight June 26, according to the Metropolitan Police Department.

Takishima had been unconscious since the accident until he was pronounced dead Saturday, the police said.

They said that during the altercation, the tip of Fukunishi's umbrella reached Takishima's brain.

Fukunishi has been in police custody since the incident. The police said he will be charged with inflicting injury resulting in death.

According to investigators, Fukunishi and Takishima got into a quarrel over their work.