Executives from Honda, Chrysler and Takata, a Japanese firm that makes around 20% of the world’s vehicle airbags, will testify today before a United States Senate committee. So far at least five deaths (four in America, one in Malaysia) and 140 injuries have been linked to Takata airbags that explode when deployed, scattering shrapnel. Around 17m vehicles have been recalled worldwide since 2008. The NHTSA, America’s road-safety regulator, says Takata and carmakers are not fixing things fast enough; politicians and safety advocates say the NHTSA could push harder. Senators will want to know who knew what, and when: in particular, when did Takata change the propellant in its airbags, and why? Takata is also the subject of a federal grand-jury investigation and more than 20 class-action lawsuits. Its share price has fallen by three-fifths this year. Meanwhile drivers worry that airbags, intended to save lives, might harm them instead.