Disputes erupted at some stations. Protesters began smashing turnstiles and ticketing machines, wrecked surveillance cameras and firefighting equipment at the stations. MTR staff were harassed and intimidated.

The city felt another shock on Sept 8, when protesters started a fire at an exit of Central Station on Hong Kong Island. Before long, arson became a standard tactic among rioting protesters. When stations were closed and shuttered, protesters smashed windows at the exits and tossed gasoline bombs inside.

Once a fixture at a metro station or a train is damaged, staff have to inspect all facilities, looking out for damage to avoid mishaps.

The uncertainties arising from attacks result in "tons of work", the manager said.