'Absolute tragedy': Baby dies after being left in car outside Sydney childcare centre

Police believe a one-year-old girl found dead inside a car at a childcare centre in Sydney had been left there for an "extended period of time" on a day temperatures hit 30 degrees.

Emergency services were called to Marana Road in Earlwood in the Inner West about 5.35pm today after the baby was found unresponsive inside the car by a member of the public.

Paramedics tried to save her but she died in what police called an "absolute tragedy".

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"Attempts were made to revive the baby, however she was unable to be saved," Burwood police area commander Superintendent Christine McDonald said.

"The information provided to us suggests that this baby was left inside the vehicle for an extended period of time on a very hot day here in Sydney.

"Leaving a child inside a vehicle at any time can be dangerous.

"Leaving a child inside a vehicle for an extended period of time can be deadly."

The male car owner, who police say was related to the baby, was taken to hospital suffering shock, McDonald said, and would speak to police when available.

The child's mother was also helping police.

Emergency services are now being offered support.

McDonald said the incident was "deeply traumatic", an "absolute tragedy" and would affect the whole community.

"I'm a mother, you can imagine how traumatic, you just – in fact, you can't even imagine it," she said.

"So no doubt the parents will be extremely upset."

" ... This has rippling effects right throughout our community, because so many of us can put ourselves in a similar situation."

Police said they were looking into the timeline of what happened.

Most of NSW is under a low-intensity heatwave warning this week, with temperatures of up to 30 degrees.