According to Ian Gregor of the FAA Pacific Division, the Beechcraft King Air crashed on departure just after 10:30 a.m. A Long Beach Airport spokesman said the plane had taken off, circled the airport and was landing when the crash happened.
It is unknown if the pilot reported any trouble, or why the plane circled and landed minutes after taking off.
The plane was engulfed in flames, but firefighters were able to quickly knock it down. An ABC7 viewer reported seeing a large fireball at the time of the crash.
There were six people on board at the time of the crash, fire department officials said. Five people were declared dead at the scene, and one man was rushed to a local hospital in critical condition.
The tail of the plane was separated from the body, and the entire plane was seen completely charred. A trail of about 150 yards was seen behind the wreckage, but it was unclear if it was burnt grass or mud.
The cause of the crash has not yet been determined.
The FAA said the plane was headed to Salt Lake City at the time.
Beechcraft King Air is capable of carrying more than a dozen people.