Boeing CEO Dave Calhoun apologized Tuesday to relatives of the victims of two 737 Max crashes during a hearing of the Senate Homeland Security Committee’s Permanent Subcommittee on Investigations.

Calhoun stood up to address the families, some of whom were holding photos of those who died in the 2018 and 2019 crashes that killed a total of 346 people in Indonesia and Ethiopia.

The CEO also faced the family of John Barnett, a Boeing whistleblower who took his own life in March.

“I apologize for the grief we have caused, and I want you to know we are totally committed to [the victims’] memory,” Calhoun said.

Calhoun said that Boeing took responsibility for the Boeing-developed key software system linked to both flights.

Calhoun testified before Congress earlier this year after a door on a 737 MAX 9 blew off during a flight from Oregon to California. Since then, the safety of Boeing planes has come into question after the company later failed 33 out of 89 audits conducted by the Federal Aviation Administration.

Another whistleblower, Sam Mohawk, came forward at Tuesday’s hearing. Mohawk currently works as a Boeing quality assurance investigator and alleged the company had hidden parts of a Boeing 737 from the FAA during an inspection.

During Tuesday’s hearing, Calhoun made remarks about Boeing’s safety history.

“I’m proud of our safety record, and I am very proud of our Boeing people,” he said. “I am proud of every action we have taken.”

Senator Richard Blumenthal, chairman of the Permanent Department of Investigation, questioned Calhoun earlier this year in a hearing with the subcommittee. On Tuesday, he said the U.S. Department of Justice has enough evidence to prosecute Boeing.

Prosecutors are reported to have until July 7 to approach a federal judge with what they intend to do. As of last week, Boeing is barred by the FAA from expanding production on the MAX.

Some information for this report came from Reuters.