Sydney commuters faced chronic overcrowding at train stations in the central city and major delays across the rail network during the evening peak on Monday, after a fatality on tracks at Wentworthville in the outer west early in the morning.

Sydney Trains advised commuters to avoid Town Hall and Wynyard stations due to overcrowding, and walk to other stations such as Central and Martin Place to catch trains, or hold off unnecessary travel due to the "major delays".

Commuters wait to enter Town Hall station, more than 12 hours after a fatality in the city's outer west. Credit:Dominic Lorrimer

Station staff at Town Hall temporarily stopped people from entering the station to avoid dangerous overcrowding on platforms during the rush hour.

The death that led to the commuter chaos late in the day occurred at Wentworthville near Parramatta at about 6.30am, resulting in police setting up a crime scene for more than three hours. The incident caused a ripple effect on train services across Sydney's rail network.