The Takata airbag recall increases by 35 million to about 63 million, about one in 4 cars in the U.S. by May 2016. The issue is connected to Takata's use of ammonium nitrate which poses a safety risk leading to explosions. The findings by 3 separate investigations from Honda Motor, Takata, and 10 automaker consortium have led to the massive recalls. A Takata engineer raised questions about the use of ammonium nitrate in the 1990's, and the company has fumbled in its response to the safety concerns.