Gao rushed to the Beijing airport, where she joined the pandemonium of families and journalists. In the hours that followed, she overheard numerous rumours regarding where the plane could have landed. She pulled a piece of paper from her bag and began jotting down notes. That night she wrote about what had transpired during the day.

For that night and 100 nights after, Gao's A4 papers became a diary. It chronicles the increasing confusion, anxiety and despair of a woman who may never know how she lost her husband.

"Last night he called me. I told him our daughter grew a new tooth on top of the old one. He promised me he would take her to the dentist today. What's going to happen now?" Gao wrote in her first entry.

Gao's husband, Li, owned factories in Malaysia and split his time between the two countries.

As the search focused on the Gulf of Thailand and the South China Sea, Gao checked her Weibo feed constantly for news updates.

She saw that analysts had written of a possibility the plane might have landed somewhere. She also read that Vietnam had spotted oil slicks near the country's coast, consistent with a plane crash. It was later determined the oil slicks came from ships.

The search zone then expanded to include the Strait of Malacca.

Rumours began to circulate of a hijacking after airline officials discovered two passengers were travelling on stolen passports.

"Just like that, 40 hours passed by without eating or sleeping, and I was still helpless." Gao wrote on March 9.

After several anxious days at a Beijing hotel, Gao decided to head to Malaysia on March 13. She hoped to get answers from Malaysian officials and be closer to the plane's last-known location.

That night at the airport hotel, several officials sent by the airline told families that the search zone had expanded to include the Andaman Sea and the Bay of Bengal. MH370, officials told the families, had lost contact at 1.20am on March 8.

Unbeknown to Gao, a day earlier, British satellite telecom company Inmarsat had told officials that MH370 had emitted pings for hours after verbal communication stopped. On March 15, news spread that the plane's last complete ping was transmitted at 8.11am, with a partial ping at 8.19am.

"This means when I called him that morning, the plane was still moving. I know what the other families are thinking, and it is exactly what I am thinking, too," Gao wrote. "The plane didn't crash, he is still alive. There is still hope. They probably landed on an island somewhere!"

The search in the South China Sea, Strait of Malacca, Andaman Sea and Bay of Bengal ended with no sign of wreckage. Days after, several experts answered the families' technical questions. Gao said she waited for a sign that her husband was still alive, but none came.

By March 17, authorities were looking for a 63-metre aircraft in a search zone that extended to roughly one-tenth of the planet.

At 9.30pm on March 24, Gao was at the Bangi Putrajaya Hotel when she received a text from another family member. It contained a screenshot of a message from the airlines:.

"Malaysia Airlines deeply regrets that we have to assume beyond any reasonable doubt that MH370 has been lost and that none on board survived. 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."

Thirty minutes later, Prime Minister Najib Razak somberly told the media that the plane "ended" in the Southern Indian Ocean. His message was broadcast worldwide.

"My mind is blank except for 'MH370 crashed, no one survived'," Gao wrote.

In a private lunch with families the next day, Huang Huikang, the Chinese ambassador to Malaysia, said the airline's decision to make the announcement without substantial evidence was irresponsible.

The ambassador said Najib's use of the word "ended" did not necessarily mean "none of those on board survived".

Hearing this, Gao's hopes for her husband lifted. "As long as there's a silver of hope, I won't give up on you," she wrote on March 25.

Meanwhile, ships from several nations were scouring the stormy, deep Indian Ocean. An Australian satellite image seemed to show debris.

Soon, China, France, Thailand and Japan released additional images. Australia and China reported that their ships had detected pulse signals. All turned out to be false leads.

On April 1, Gao returned home.

"I haven't seen our daughter for 20 days, and the first thing she tells me is 'I miss daddy'," Gao wrote. "I don't want to tell her what happened yet.

"I see you everywhere: in our wedding picture on the wall, in our closet, in our study, on the computer. Come back soon."

Gao returned to work. She had examined every detail of the disappearance. She had checked every conspiracy theory on the internet.

On April 10, she wrote that she had experienced a full spectrum of emotions and could no longer feel. She found comfort only when discussing MH370 with other relatives of those on board

"News of the plane dwindles everyday, I'm afraid the world will forget about you," Gao wrote on April 17.

Frustrated members of other families continued to lobby the international media, Beijing, the Malaysian government and Malaysia Airlines, demanding that their loved ones be returned.

Some in Beijing staged a hunger strike on April 25.

May 5 was especially hard for Gao.

"There's been an outpouring of support from our friends, some of whom I hadn't spoken to in decades. It makes me think of how important it is to have friends and family," she wrote. "These days, I don't cry much anymore, but today is your birthday. I held the Oral-B toothbrush I got you for your birthday last year and cried."

One hundred days after MH370's disappearance, relatives of the missing are divided over how to proceed, with many in different stages of grief.

A few have accepted that their loved ones are dead.

Most say they refuse to rest until the plane is found, and their loved ones' DNA confirmed.

Gao spent the month of May contacting international lawyers. But a potential lawsuit is complicated by the fact that there's no plane, no black box, and no useful clues. Who should she sue and for what?

Yesterday, she ended her 100th diary entry with "will I ever see you again?"