AN APARTMENT building in Sydney's inner west with 100 people inside is on the verge of collapse, after more than a month's worth of rain fell in some parts of the city this morning.
State Emergency Service crews have arrived at the Marrickville building, after also fielding multiple calls throughout the morning to rescue people from flood waters.
Marrickville volunteers are en-route to a building threatening to collapse. 100 people are inside. More to come.#NSWSES— NSW SES (@NSWSES) February 7, 2017
Buses and trains have been delayed by up to an hour and some roads across the city remain closed or gridlocked as drenching rains continue to fall.
The rain also looks set to continue throughout the day and into tomorrow.
The weather bureau issued a severe thunderstorm warning just before midday but cancelled it an hour later.
There remains in place a thunderstorm warning for heavy rainfall and damaging winds.
Flooded roads have caused chaos for motorists and there are continuing delays on bus and train routes.
James Ruse Drive and Parramatta Rd flooded and the Anzac Bridge was gridlocked, though traffic started moving again when floodwaters subsided.
Buses to and from Drummoyne and Rozelle were suffering delays of up to an hour at the peak of the rainfall due to being diverted around Anzac Bridge.
As of 2pm, there remains residual delays of up to 30 minutes on those routes.
Trains on the T2 line were not stopping at Lewisham station due to flooding in the subway but resumed about 1.30pm.
Flights have also been impacted at the airport, where heavy rain has fallen.
A Fire and Rescue NSW spokeswoman told The Daily Telegraph crews had been swamped with requests for help, as the storm caused roofs to cave in, homes to flood and cars to become trapped.
"On Wentworth Rd in Glebe the water has been reported up to one metre deep and there are requests for a vehicle to be towed out," the spokeswoman said.
"We urge people to stay away from flood waters and not risk their safety by trying to drive through flood waters or walk through them."
The city, the inner west and the east are copping the worst of the rain.
Nearly 50mm has fallen at the city's Observatory Hill meteorological site since 9am, while the airport has had 26mm.
Nearby Canterbury has had 46.6mm.
Flight delays, diversions and cancellations are expected at Sydney Airport.
Worse could be on the way.
The Bureau of Meteorology issued a severe thunderstorm warning just before noon, saying the bad weather is likely to hit the city's far west by 12.25pm and Parramatta, Sydney Airport, Sydney Olympic Park and Penrith just before 1pm.
Bureau of Meteorology forecaster Mohammed Nabi said more heavy rain is expected throughout the day and into tomorrow.
"The thunderstorms combined with the humid air over the city is causing this," he told the Daily Telegraph.
"When you get these sorts of downfalls, they can cause flash flooding in built-up areas."