LOS ANGELES (CBSLA.com) — The families of four of the six victims who were killed in a plane crash along with singer Jenni Rivera have filed a wrongful death lawsuit against the company that owned the plane, which crashed at more than 600 miles per hour.

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Starwood Management LLC, which owned and operated the Learjet 25, has been named in the suit. The families are blaming the company for negligence in allowing the plane to take flight.

Records show the jet, built in 1969, was heavily damaged during a 2005 landing and then later cleared to fly by officials.

According to documents, Starwood Management also had one of its planes seized by the U.S. Drug Enforcement Administration in September.

Rivera’s company, Rivera Enterprises, has also been named in the suit.

“Likely, it was Rivera Enterprises that negotiated and arranged this flight, and that’s why Rivera Enterprises is a named entity,” attorney Paul Kiesel said.

The crash in the mountains of Northern Mexico on Dec. 9, 2012, killed Rivera, her publicist Arturo Rivera, her makeup artist Jacobo “Jacob” Yebale, her stylist Jorge Armando Sanchez Vasquez, her attorney Mario Macias Pacheco and the flight crew.

According to reports, the plane hit the ground 1.2 miles from where it began falling, plummeting at a nearly 45-degree angle from more than 28,000 feet.

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“The aircraft suffered some, as yet, unknown event that caused this 1969 aircraft, a plane that was older than every single passenger, save the pilot…” Kiesel said.

The lawsuit states the 78-year-old pilot and his 20-year-old co-pilot were “insufficiently trained, improperly licensed, dangerously unfit and inexperienced…”

The suit also claims the pilot wasn’t authorized to fly above 18,000 feet nor carry passengers, and the co-pilot wasn’t licensed to fly the model of Learjet that was carrying Rivera and her staff.

KNX 1070 reporter Charles Feldman, a pilot who has been flying small planes for 20 years, said such a fall points to a few possible causes of the crash.

“One would be some sort of catastrophic failure of the aircraft frame. Another possibility would be the crew, in this case the pilot and the co-pilot, being incapacitated,” he said.

The lawsuit seeks unspecified damages.

Attorneys said they believe Rivera’s family will also file a lawsuit against Starwood Management.

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