SAN DIEGO -- A San Diego man who lost his family when a military jet crashed into their home filed a lawsuit against the U.S. government and the jet's manufacturer.

The December 2008 crash in University City claimed the lives of Don Yoon's wife, two young daughters and his mother-in-law.

"I believe my wife and two babies and mother-in-law are in heaven with God," Yoon said the day after the incident.

Attorney Kevin Boyle, who is representing Yoon, told 10News his client is still living in San Diego and is having an incredibly hard time moving on.

"He hasn't been able to return to work, and he's living in relative solitude just trying to cope with his emotional issues," said Boyle.

This week, Yoon's legal representatives filed a lawsuit against the federal government and jet manufacturer Boeing. The complaint cited negligence, stating: "The jet had a history of warnings and system failures known to the defendant, United States and the jet's manufacturer …"

Meanwhile, a Marine investigation released last year determined it was the jet's pilot, Lt. Dan Neubauer, and ground crews who made a major mistake when the jet's engines failed.

"The pilot did not reference his checklist for this caution and did not realize that step two of the emergency procedure for a fuel-low caution ... is to land as soon as possible," according to investigation documents.

Investigators said the pilot should have landed at Naval Air Station North Island, but instead tried to make it to Marine Corps Air Station Miramar. Seconds before reaching Miramar, the jet ran out of fuel and Neubauer ejected. The F/A-18 crashed directly onto Yoon's home.

"You can imagine your entire family -- young family -- burning alive … there's really nothing worse that can happen," said Boyle. "I think the gravity of his loss has settled in on him, and I think he's on the road to recovery … but it's going to be a long road."

10News learned Neubauer has been promoted to captain and was allowed to resume his flight training in April 2009.

A military spokesman said Neubauer is currently flying with the 2nd Marine Aircraft Wing in Buford, South Carolina.

The amount sought in the lawsuit will be determined in the coming weeks, 10News reported.