Mike Murchison, who's a local business consultant and spokesman for developer Tom Dean, says Dean, developer Jeff Berger and bicycle advocate Mark Bixby were killed in the crash. The identities of the other two people who died weren't immediately available.
Murchison says another passenger, Mike Jensen, is hospitalized in critical condition.
The Long Beach Airport director says the Beechcraft King Air turboprop had taken off but was circling back when it crashed and burst into flames at about 10:30 a.m. Wednesday.
The cause of the crash is under investigation.