"Kia is now evaluating a remedy for this recall".
Kia will recall more than 500,000 cars due to an air bag flaw by the end of July, an NHTSA release shows.
NHTSA's investigation remains open, the agency said in a statement Friday afternoon. In these crashes, four people were killed and another six were injured.
The agency said would evaluate the Hyundai-Kia problems and will investigate whether any other vehicle manufacturers used the same or similar ZF-TRW air bag computers. The crash of the 2013 Forte occurred in Canada.
Included are the 2010 through 2013 Forte, 2011 through 2013 Optima, and Sedona and Optima Hybrid minivans made in 2011 and 2012.
In the affected vehicles, the air bag control unit may short circuit and prevent the front air bags and seat belt pretensioners from deploying in a crash, according to the NHTSA recall notice.
Unfortunately, Kia doesn't have a fix for the issue yet, but it said it's already working on one with its supplier.
In May of a year ago, NHTSA opened an investigation into whether Hyundai and Kia moved quickly enough to recall more than 1.6 million cars and SUVs because the engines can stall, increasing the risk of a crash.