Less than an hour later, Saturday's meeting had unraveled. A few dozen relatives rose from the gymnasium floor and surged toward the stage, hurling rapid-fire questions - and a thick, rolled-up wad of paper - at the officials, who stood mostly silently, their heads bowed. One man tried to choke a coast guard lieutenant and punch a maritime policeman, but missed.
The exchange illustrated how relatives of about 270 people missing have grown increasingly exasperated and distrusting of South Korean authorities, in part because of confusion, early missteps and perceived foot-dragging. For days, they have dealt with shock, fear and bewilderment. They have briefly been buoyed by new ideas about how to find survivors, changes in death counts and the number of missing - even rumors of contact with trapped relatives - only to be let down later.
The mood in the gymnasium on Jindo island where hundreds of relatives are waiting for word about their loved ones is generally a somber calm. People murmur to each other or sit silently, staring at the screens that show pixellated footage of ships, rescue rafts and yellow bobbing buoys. Some relatives busy themselves with folding blankets or tidying the spaces they've been living in. Some walk around looking dazed or weep in a friend's embrace.
They're getting help for many needs. Volunteers set up charging stations for cellphones and distribute food and drinks. First aid officers take care of those who have collapsed from exhaustion and grief, hooking them up to glucose intravenous drips. Police have set up a tent where some relatives have given DNA samples, in case they help identify bodies later.
But the seeds of distrust were planted Wednesday, the day the ferry sank with 476 people aboard, 323 of them from a single high school in Ansan. Thirty-three bodies have been found, and 174 people survived the disaster.
The high school initially sent parents text messages saying all of the students had been rescued.
Lee Byung-soo, whose son was aboard the ferry, was relieved by the text. He called the maritime police to ask whether there were enough life jackets for all of the students, and whether the water was very cold. The answer, he said, added to his confusion.
''They said all the students were wearing life jackets. When I asked more, they told me to get information from a briefing later,'' said Lee, a truck driver.
It was only when he arrived at the gymnasium that he realized his son, 15-year-old Lee Seok-joon, had not been saved. ''I had to check every picture of the face of the rescued students before I realized that my son was not there,'' he said.
''The students were killed because the crew members and teachers and adults told them to crawl in the cabin and stay,'' Lee said, weeping as he spoke in the gymnasium.
The ferry's captain - who was arrested Saturday along with two crew members - has drawn criticism for waiting about 30 minutes to order an evacuation, by which time the boat had listed so steeply many could not escape. Relatives also are angry over the government's response.
''I know this has been a very difficult situation,'' said Lee Jong-eui, a businessman whose 17-year-old nephew, Nam Hyun-chul, is among the missing. ''But aren't people supposed to have faith in the government The government should have hurried up and have done something, but they just wasted four days, which led to this point. I think this is more like a man-made disaster.''
Saturday's briefing began with a family member presenting video footage shot by a diver using a head-mounted camera the night before. The only sounds that could be heard in the gym were the diver's breathing as he gripped a rope with gloved hands and used a flashlight to illuminate the murky water. The diver could be seen pulling the rope as he advanced toward the sunken ship. Dust and sediment washed around in various directions, testifying to the rapid changes in sea current. Glimpses of the ferry could be seen - metal railings and a small window.
Shin Won-sup, special rescue forces lieutenant of the coast guard's south regional headquarters, had barely started explaining the operation when a man in a blue jacket interrupted him.
''Wait, what we want to know is the inside of the ferry. Why weren't you able to film that'' the man asked.
''We weren't able to go in,'' Shin replied. When he repeated that none of the divers had been able to get inside, the silence from the crowd exuded dissatisfaction.
The questions and accusations quickly mounted:
''You guys just filmed this video to show off to President Park (Geun-hye). To make excuses for yourself.''
''Why did you refuse to take the rescue gear and supplies that foreign countries offered''
''We waited here all this time, trusting these people.''
Many family members rose to their feet and approached the stage as the rescuer ducked behind an LED screen. The relatives continued shouting.
''Now that 72 hours has passed, just pick up the dead bodies Is that what you're saying''
''Would you have done the same if your own children were in the water''
One woman climbed onto the stage and went behind one of the screens to demand that Shin and other officials come out to talk to the relatives. The rescuer and two maritime police officers slowly emerged, looking sheepish. Women shouted and yanked at the arms of one officer. A man jumped up and grabbed Shin by the neck but was pulled off by other relatives, but not before he swung at a policeman.
The venting ebbed as some relatives collapsed in tears. A diver would come later to talk more about the difficulty of the search, but for the moment the officials backed away, out of sight.
Associated Press researcher Minjeong Hong contributed to this report.