A woman chasing her dog across a busy Sydney street suffered critical injuries when she was hit by one car and thrown into the path of a second vehicle that dragged her along the road before the driver sped off.

Police are hunting the driver of the second car who left Lan Cliff, 47, for dead.

Ms Cliff, a housekeeper, was crossing Fitzgerald Ave, Maroubra, about 7.15pm on Friday night when she was struck by a Toyota Corolla driven by a 19-year-old man.

Ms Cliff was then hit by ­another vehicle travelling in the opposite direction. She was dragged about 10m towards the intersection with Nagle Ave.

While the 19-year-old driver of the first car stopped and started first aid, the driver of the second vehicle drove off.

“I saw her lying face down and there was blood all over her head and back,” one witness, who did not want to be named, said.

“I’ve never seen anything like it. It was horrible. There were a number of people who stopped and gave her first aid.”

One person said they heard the driver of the Toyota say: “She just stepped out in front of me.”

A neighbour said that Ms Cliff’s husband, Brett Cliff, “was in a lot of shock”.

“He had to go into the gutter and get his dog, scoop it up and walk it into his backyard. I think at this point it was gone,” the neighbour said of the couple’s 12-year-old boxer dog named Coco, who died in the accident.

Ms Cliff was taken to St George Hospital in a critical condition.

Rochelle Leonard, 45, used to work with Ms Cliff at Stamford Plaza at Sydney Airport. She described her former work colleague as a very caring and happy person.

“It is unfathomable that someone is out there and has not handed themselves in,” Ms Leonard said of the driver who remains at large.

“Lan is critically ill and could possibly die.

“This is not something that you sweep under the carpet. Surely you can’t keep this sort of stuff bottled up.”

NSW Police Acting Inspector Naomi Earle said the behaviour of the second driver was “concerning”.

“We are hoping that this driver will have a conscience and come forward. We will track them down,” she said.

NSW Police Highway Patrol Commander Assistant Commissioner Mick Corboy said detectives were still trying to find the driver.

“We found a dumped vehicle which we are examining — it may or may not be the one,” he told The Sunday Telegraph.

“We are trying to track down the owner and hopefully speak to them soon.”