Six months have passed, and Clariss Moore is still haunted by the phone call she never made.

It was March 10. Her daughter Danielle was at the airport in Addis Ababa, Ethi­o­pia, preparing to board a flight to Kenya, where she was scheduled to attend the U.N. Environment Assembly.

Moore wanted to call her but didn’t because she was worried it would make her daughter late for her flight.

“Now I wish I’d called her,” Moore said Tuesday. “I wish I had called so she would have missed that plane. And I will continue to live [with] that regret until the day I die.”

Danielle Moore, 24, was one of 157 people killed when Ethio­pian Airlines Flight 302 crashed shortly after takeoff from Addis Ababa Bole International Airport. The crash, the second involving a Boeing 737 Max jet in less than five months, led to the worldwide grounding of the aircraft.

The crashes also led to an examination of how U.S. regulators certify an aircraft as safe and whether manufacturers have an outsize role in that process.

While both crashes remain under investigation, investigators say an automated anti-stalling feature known as the Maneuvering Characteristics Augmentation System, or MCAS, repeatedly pushed the planes’ noses downward, thwarting the pilots who were struggling to regain control. The system was reacting to faulty information from the planes’ “angle of attack” sensors, according to preliminary investigative results.

On Tuesday, families of the victims of Flight 302 marked six months since the crash with a vigil in front of the Transportation Department’s headquarters in Washington.

Holding photos of family members, they spoke of the difficulty of coping with losses so deep and shattering there seems to be no end to the pain.

“While all of you have moved on in the last six months, my life has not moved an inch,” said Paul Njoroge of Toronto, who lost his wife, three children and mother-in-law in the crash. “I don’t know how to live my life.”

Chris Moore called his daughter Danielle his family’s “Miss Incredible” and described her as a woman with a big heart, determined to make the world a better place.

“A big chunk of us died in that crash,” he said.

Zinet Adem of Beltsville remembered his brother Mulusew Alemu, a 36-year-old who worked as a finance officer for Catholic Relief Services, as “a very loving, honest, kind person.”

“We’re here to tell the world, please stand with us,” Adem said. “We want the aviation industry to be safe.”

Also remembered was passenger Cedric Asiavugwa, who was only three weeks away from graduating from Georgetown University Law School when he was killed.

Family members also expressed anger that it took a second crash of a 737 Max for regulators to take action.

A Lion Air 737 Max had crashed into the Java Sea off the coast of Indonesia on Oct. 29, killing all 189 people aboard.

“It is not fair that so many lives were lost but no one lost their job,” Clariss Moore said.

Earlier Tuesday, the families met privately with Transportation Secretary Elaine Chao.

Nadia Milleron, whose daughter Samya Stumo, 24, was killed in the crash, said she was heartened by the meeting.

“It was important for her to hear all the families’ stories,” said Milleron, who helped organize the vigil.

Milleron said the families made two specific requests of Chao — that the 737 Max not be allowed to resume service until it has gone through the full certification process again and that pilots not be allowed to fly the planes until they have been trained in simulators. Previously, pilots trained for the jet on iPads.

“We appreciate the opportunity to meet with several family members today and their dedication to improving aviation safety following the tragedy of Ethiopian Air Flight 302 on March 10, 2019,” the Transportation Department said in a statement. “Our hearts go out to these families and all those who have lost loved ones.”

Chao and Congress have launched several reviews of the crash and of the Federal Aviation Administration’s handling of the certification process. Chao formed a special committee — led by Christopher Hart, former chairman of the National Transportation Safety Board, and including representatives from Canada and Indonesia — to examine certification.

She also has asked the agency’s inspector general to conduct an independent review of the FAA’s certification process.

The families had originally sought a meeting with FAA Administrator Stephen Dickson but said they were told he could not meet with them because of scheduling issues.

The FAA did not address that claim, saying in a statement only that “Administrator Dickson has said from the beginning of his tenure that he will meet with the families, and he will honor that commitment.”

FAA officials have said there is no timeline for returning the 737 Max to service.

Boeing is working on a software update to fix the MCAS and other problems that have been discovered during the investigation.

“The FAA’s certification of the Boeing 737 Max is the subject of several independent reviews and investigations,” the FAA said Tuesday.

While the agency has continued to defend the certification process that led to the approval of the jet, officials said they welcome the additional reviews.

“We continue to work with other international aviation safety regulators and will carefully consider all recommendations,” the agency said. “The FAA will incorporate any changes that would improve our certification activities.”