A man was hit by a subway train and died in a subway tunnel in Nanjing, East China's Jiangsu province on Sunday, causing a 12-minute delay of the city's underground transportation, the Yangtze Evening New reported.

The driver of the subway said he saw a man walking on the rail 30 meters ahead when he drove away from the Nanjing south station around 10:40 am. He put on the emergency brake immediately, but still it was too late to avoid the accident, the report said. All subway stops have glass safety gates, but no one knows how the victim made his way onto the rail.

The cause of the accident is under investigation.