The Orange County Fire Authority said fire and rescue units were sent to a the 3900 block of Bristol Street for a report of a plane down.
The plane was heading to the airport southeast of Los Angeles and had been cleared to land when it came down in the parking lot of a Staples store and a CVS pharmacy, NTSB officials said.
The resident's father used to fly planes, she had a feeling that something was wrong.
The plane was en route to nearby John Wayne Airport when the pilot declared an emergency and crashed around 12:30 pm local time in Santa Ana, near the South Coast Plaza shopping mall, the authorities said.
The family of one of the victims identified their daughter, 29-year-old Nasim Ghanadan of Danville, as one of those aboard the plane when it crashed.
Lara Shepherd, Floria Hakimi and Ghanadan were all Realtors with Pacific Union International, the eighth-largest real estate brokerage firm in the country, according to the company's website.
There were no other passengers in the plane, and nobody on the ground was hurt.
Capt. Tony Bommarito of the Orange County Fire Authority said the accident could have been much worse.
Bystanders told journalists they saw the plane falling nose-first.
The FAA arrived on the scene about 4 p.m. and the National Transportation Safety Board representatives were expected this evening, Bommarito said. A phone call to the company was not immediately returned Sunday.