Honda Motor on Friday confirmed that a rupturing airbag inflater fatally wounded the driver of a 2005 Civic in a crash in April. Counting this, at least seven deaths have been linked to defective airbags made by the Japanese supplier Takata.

Kylan Langlinais, 22, died in a hospital four days after the Civic she was driving crashed into a utility pole in Lafayette, La., according to a lawsuit filed this week by her family. The airbag exploded and sent metal fragments into Ms. Langlinais’s car, severing an artery in her neck, the lawsuit said.

The vehicle was included in what Honda called a “safety improvement campaign” announced in June 2014, but no notice was sent to the car’s owner at the time, the automaker said. Ms. Langlinais acquired the vehicle in October 2014.

Honda finally sent a safety notice for the car on April 2, three days before Ms. Langlinais’s crash.