Following a fatal incident involving an ARC airbag in Canada, the National Highway Traffic Safety Administration is opening an investigation into airbag manufacturer ARC Automotive Inc. for airbags that could deploy with too much force. The investigation covers General Motors, Fiat Chrysler Automobiles, Hyundai Motor Company and Kia Motors Inc totalling over 8 million inflators, according to Automotive News.

The NHTSA will “direct the collection and testing of inflators as part of its effort to determine the root cause of the rupture incidents,” said NHTSA spokesman Bryan Thomas. The latest episode on airbag inflator incidents comes after a series of occupant fatalities related to Takata airbag inflators, which has rendered more than 100 million vehicles worldwide considered defective.

The investigation was prompted when a driver in Canada was killed in a 2009 Hyundai Elantra, which was equipped with an ARC airbag. The unit involved in the Canada incident was made in China, but the NHTSA said the US market 2009 Elantra did not use the same airbag.

NHTSA also said the ARC inflators are a hybrid design using high-pressure stored gas and a small amount of ammonium nitrate to inflate the airbags. It said its preliminary investigation shows “significant design differences between the ARC inflators and the Takata inflators currently under recall.”

Initially an investigation was opened on 490,000 vehicles in July 2015 following two reported injuries, in a 2002 Chrysler Town & Country and a 2004 Kia Optima, after inflators produced by ARC in Tennessee ruptured.