The U.S. National Highway Traffic Safety Administration announced Thursday it is fining Honda Motor Co.'s U.S. division $70 million for not reporting hundreds of complaints that its vehicles caused death and injury. It’s the largest civil penalty ever levied against an automaker for failing to keep the public informed about alleged dangerous flaws in the vehicles it sells in the U.S.

Automakers are required under the TREAD Act to disclose serious complaints to federal regulators. Honda acknowledged in November that it failed to report to the U.S. National Highway Traffic Safety Administration (NHTSA) 1,729 complaints dating back to 2003 that its vehicles caused deaths and injuries. Honda admits it was aware of the failing in 2011 but didn’t comply until late last year. The company is not disputing the penalty.

"What we cannot tolerate and will not tolerate is an automaker failing to report to us any recall issues," Transportation Secretary Anthony Foxx told the Associated Press.

The issue not only tarnishes Honda’s reputation, but also NHTSA’s, which has faced public scrutiny for its handling of auto safety oversight after 2014 became a record year for automotive safety recalls, topping 60 million vehicles. The House Energy and Commerce Committee slammed NHTSA for its handling of the General Motors ignition-switch recall last year that’s linked to at least 42 deaths.

The complaints against Japan’s second-largest automaker involve defective parts, especially air bag inflators made by Takata Corp., Honda’s longtime supplier of auto safety components. The air bags can inflate with explosive force, spraying bits of metal into the driver. Honda issued recalls covering more than 5 million of its vehicles in the U.S. last year to fix the problem.

Mark Rosekind, a fatigue expert and former member of the National Transportation Safety Board, was confirmed as the new NHTSA head. He replaced acting NHTSA administrator David Friedman, who served since January 2013, a month after David Strickland resigned to become an auto regulation lobbyist. During his tenure, Strickland was instrumental in advising lawmakers about self-driving cars.