A Japanese university student in Kyiv who took shelter in an underground parking garage while Russian missiles rained down on the capital started posting messages on social media to describe his harrowing experience as invading Russian forces advanced across Ukraine.

Tsuyoshi Maehara, 20, a second-year student at Tokyo’s Keio University, has been studying in an integrated information technology project known as the Innovation Park Unit City in the Ukrainian capital since late January.

“I didn’t sleep a wink,” he responded after being contacted on the morning of Feb. 25. “It is extremely cold. But I feel safer here than at home.”

Maehara said he decided to start posting on social media to leave a written account of what was happening in the event he did not survive.

Maehara wrote that he evacuated to an underground parking garage along with 20 or so other Kyiv residents after sirens sounded around 5 a.m. on Feb. 24 as explosions rocked the Ukrainian capital.

In an earlier message, he said: “It is very difficult because I have no idea what is going on. I have never had such dry tears flowing from my eyes.”

He also expressed his fears for his Ukrainian male friends as those aged between 18 and 60 were being called to join the fight against Russia.

Maehara fled to the garage late Feb. 24 as panic spread over fears Russian troops would soon move into Kyiv. He and the others spent the rest of the night trying to fend off the bitter cold.

In another message, Maehara appealed for help to allow him to escape from Kyiv.

“I earnestly hope that Japanese still here as well as my many Ukrainian friends do not lose their lives,” he wrote.

One message was retweeted about 40,000 times by 6 p.m. on Feb. 25.

Maehara said he had been using social media to communicate with his family in Japan, adding, “I don’t want them to worry, so I have maintained an upbeat tone to tell them that I am all right.”

The last message he sent said: “I hope that the world becomes one in which society, people’s souls and the world can all feel happiness. I ask for your help to support Ukraine.”