One woman collapsed and fell on her knees, crying "My son! My son!"
Medical teams arrived at the Lido hotel with several stretchers and one elderly man was carried out of the conference room on one of them, his face covered by a jacket. Minutes later, a middle-aged woman was taken out on another stretcher, her face ashen and her blank eyes seemingly staring off into the distance.
Most of the relatives refused to speak to gathered reporters and some lashed out in anger, urging journalists not to film the scene. Security guards restrained a man with close-cropped hair as he kicked a TV cameraman and shouted, "Don't film. I'll beat you to death!"
Some relatives staying at hotels in Beijing and Kuala Lumpur were notified in person of the imminent late-night news conference by Malaysian Prime Minister Najib Razak, and some heard over the phone.
Some received a heads-up by text message, said Sarah Bajc, who has been awaiting news of the fate of her boyfriend, Philip Wood, ever since the plane disappeared March 8 on a night flight from Kuala Lumpur to Beijing with 239 people aboard.
"Malaysia Airlines deeply regrets that we have to assume beyond any reasonable doubt that MH370 has been lost and that none of those on board survived," the text message said. "As you will hear in the next hour from Malaysia's Prime Minister, we must now accept all evidence suggests the plane went down in the Southern Indian Ocean."
Bajc noted in an email that the prime minister's announcement made no mention of confirmed wreckage, "so no real closure," but she also said the time for grief had begun.
"I need closure to be certain but cannot keep on with public efforts against all odds. I STILL feel his presence, so perhaps it was his soul all along," she wrote. "It looks like the first phase of our mission has ended. Now Philip's family and I will need some time for private grief."
Wang Zhen, whose father and mother, Wang Linshi and Xiong Yunming, were aboard the flight as part of a group of Chinese artists touring Malaysia, said he heard the announcement on television in the hotel where he has been staying.
"My mind is a mess right now. Can we talk later?" he said by telephone.
Nan Jinyan, whose brother-in-law Yan Ling, a medical company engineer, was aboard the flight on a business trip, said she was prepared for the worst when she heard the Malaysian prime minister would make a statement.
"This is a blow to us, and it is beyond description," Nan said.
At the Lido hotel, where many of the Chinese relatives have complained about what they have described as incomplete or contradictory information provided by the airline and Malaysian authorities, two distraught women and a man came to address journalists nearly two hours after the announcement.
"I tell you, this was the wrong way to release this information," one of the women said between sobs, speaking over the bellows of security guards trying to hold back the crush. "It's all so black," she said, using the Chinese expression for opacity and deceit.
In Kuala Lumpur, screaming could be heard from inside the Hotel Bangi Putrajaya, where some of the families of passengers have been given rooms.