Flames consumed an upper floor of an ocean-front high-rise residence late Wednesday, and one person died after jumping from the 20-story building, authorities said.
A crowd of about 25 to 50 people saw the person plunge off the building, said Craig Dodd, a freelance news videographer who captured the incident on tape.
"There was a person up there yelling and screaming. While I was videotaping, he did decide to jump. He had no choice at that point," Dodd told KNBC-TV.
"He was calling for help several times, and obviously the fire department was doing a great job, moving as quickly as they could. But unfortunately he had no choice at that point," Dodd said.
The fire began on the 18th floor of Galaxy Towers about 9:30 p.m. (0430 GMT Thursday), said fire Capt. Jim Arvizu. It was not immediately known whether flames spread to other floors.
About 70 firefighters responded to the scene, evacuating an unknown number of residents.
The death and cause of the fire were under investigation.
Long Beach, a populous seaside city, is located about 25 miles (40 kilometers) south of downtown Los Angeles.