"I was upstairs and all of a sudden the house just shook and I thought, 'Oh my gosh, we're having an earthquake,'" said Marian Michaels, who lives behind the home where the helicopter crashed.

The four-seat Robinson R44 went down in a gated community in Newport Beach, about 72km southeast of Los Angeles.

Four people were on board the helicopter. The injured were taken to hospitals but there was no immediate word on their condition.

Roger Johnson was doing some woodwork in his garage when he heard the sound of a helicopter and then a tremendous boom across the street.

Three deaths and injuries

"I turned to look out of the garage and that's when I see this piece of metal flying through the air and hitting a bush and garage door," Johnson said.

"Then I heard someone scream - a real for-real horror scream, like something terrible had happened."

Johnson rushed to the wreckage and several people started to try to pull victims out of the helicopter. That's when Johnson urged them not to move them for fear of further injuring them.

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Fire Chief Chip Duncan confirmed the three deaths and injuries but could not say how many of the dead were aboard the aircraft.

A neighbour who heard the crash told KCAL-TV that he saw the pilot lying injured but alive on the grass and three other people inside the wreckage.

"We tried to pry them out but we didn't want to touch them," said the neighbour, who was not identified by the television station. "We didn't want to take a chance of hurting anybody."

"The three people were all crunched in there together," he said. "One I could see moving an arm."

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