A worker was installing a seat belt air bag replacement on a 777 at Boeing's Everett factory and the unit inflated explosively causing severe head injuries to the man. A month later, the man died. Now, the family of that man has filed a case against Boeing Co. and the air bag manufacturer, AmSafe.

This week, the case was filed in King County Superior Court. As per the lawsuit, Singapore Airlines, the plane's buyer, found a discharged air bag in a business-class seat.

As per the lawsuit, neither Boeing nor AmSafe carried out an examination to know what led to the malfunction. It was later found that the air bag has discharged because of a short circuit in the wires that control the device.

Boeing asked Jamco America Inc., the company that installs the 777 air bags, to replace the device on the plane. Being a Jamco employee, Kenneth Otto and Christopher Gee from Vartan Aviation Group, which works on Boeing airplane interiors, came to correct the things.

The lawsuit stated that Otto had installed more than 150 AmSafe seat belt systems at the Jamco factory before they were installed in the plan. But Jamco and Vartan workers have not installed a NexGen AmSafe air bag seat belt system on a seat on Boeing aircraft.

The suit states, "Boeing required the work be performed within the tight confines of the airplane. No further guidance or assistance was provided to the two workers".