Two prominent real estate developers and a bicycle advocate were among five people killed Wednesday in the fiery crash of a twin-engine plane at Long Beach airport, a spokesman for one of the victims said.

Developers Tom Dean and Jeff Berger, and advocate Mark Bixby were killed, Mike Murchison, a spokesman for Dean, said in an e-mail to The Associated Press.

The identities of the other two people who died weren't immediately available.

Another passenger, Mike Jensen, was hospitalized in critical condition, Murchison said.

The privately owned Beechcraft King Air turboprop had taken off but was circling back when it crashed and burst into flames, Long Beach Airport Director Mario Rodriguez said.

He did not immediately know why the plane had turned around. The cause of the crash was under investigation.

Rodriguez said the crash closed two taxiways and one of the airport's five runways. Commercial flights were not affected, he said.

The front half of the plane and its wings came to rest on a grass median between two taxiways.

The plane left a scorched trail dozens of feet long as it plowed through the grass.

The burning plane sparked a small ground fire that was quickly extinguished, Deputy Fire Chief Jeff Reeb said.

Murchison said the plane belonged to Dean, who also owns most of the Los Cerritos Wetlands in southeast Long Beach. Part of the wetlands was traded last year to the city in exchange for most of its public service yard in a land swap.

Berger was Dean's business partner.

The plane was departing for Salt Lake City when it went down, said Ian Gregor, a spokesman for the Federal Aviation Administration. An FAA website said the plane was registered to a Los Angeles company called Carde Equipment Sales LLC. There was no public phone listing for the company.

It was the first crash at the airport in more than 30 years, Rodriguez said.