"For that intensity and that duration, that’s the sort of rainfall you’d expect to occur about once every 100 years for that particular site," Bureau of Meteorology's NSW manager Ann Farrell said. The city’s average for the month of November is 83.8 millimetres. A flooded Jubilee Oval in Glebe on Wednesday morning. Credit:David Porter Fatal accidents On Wednesday night, the NSW State Emergency Service said that a volunteer member died after collapsing on duty. Seven News reported the man in his 40s was assisting with their rescue efforts at Flinders, south of Wollongong. The man reportedly suffered a heart attack before collapsing.

About 7pm in South Wentworthville, a man died after the car he was driving crashed into a pole off Old Prospect Road. The man was treated at the scene by paramedics but could not be revived. A male passenger was uninjured. Earlier a 14-year-old boy from Westleigh, in Sydney's north, died in a car accident at Thornleigh. Police said the car collided head-on with another vehicle before hitting a parked car. A police officer also suffered a suspected broken leg and another officer was left concussed after a tree fell on them when they were assisting motorists during flash flooding on Pittwater Road. Flash flooding coincided with the morning commute, closing a number of major roads, the cancellation of all light rail services, flight delays and cancellations and train delays on the T1, T2 and T3 lines.

“The conditions we are experiencing [on Wednesday] are some of the worst I’ve ever seen,” NSW Police Assistant Commissioner Michael Corboy said. Loading Authorities responded to nearly 50 crashes, around four times the daily average, during a six-hour window at the peak of the morning's bad weather. "In my 12 years here we’ve certainly seen some sustained poor weather, but nothing like this, we are really urging people to slow down and not drive if possible,” NSW Ambulance Acting Superintendent Steve Vaughan said. Other major thoroughfares including Parramatta Road at Concord, the Western Distributor and Anzac Bridge at Pyrmont were partially closed or experienced significant delays at the height of the storm.

Trains were also impacted with Town Hall station experiencing a partial roof collapse and Lewisham station experiencing flooding. It reopened on Wednesday evening, but delays were still expected with emergency buses on standby during the evening peak. Sydney received more than 118 millimetres of rain on Wednesday. Credit:Louise Kennerley Calls for help The SES responded to more than 800 calls for assistance mostly for leaking roofs and fallen trees and performed 15 flood rescues.

“The number is really quite concerning, so we want to push a message to urge people not to drive through flood water,” an SES spokesman said. “People driving in the peak rain this afternoon need to keep clear of low-lying areas, and should not park their vehicles under trees or power lines.” Flooded roads were a major issue across the city on Wednesday. Credit:Nick Moir More than 100 flights were cancelled or delayed as Sydney Airport repeatedly closed one of its runways as wind gusts of up to 70km/h were recorded just after midday. Sydney's highest winds hit at Wattamolla, in the Royal National Park south of Sydney, with a gust of 96km/h just before 4.30pm.

North Head also recorded a gust of 90km/h at 2.24pm. Loading At its peak, thousands of properties were without power. In Chatswood, a tree brought down power lines over the road while a tree on power lines also affected power supply in Roseville. Ausgrid had restored outages in East Ryde, North Ryde and Marsfield by around 3pm. Economic cost