His body was due to leave Bangkok's Siriraj Hospital for the Grand Palace, where his funeral rites will be carried out.
Somdej Phrawannarat, a much-revered monk, will lead the procession, the palace said. Phrawannarat is a leader at a Buddhist temple that is important to the King's Chakri Dynasty. He will be followed by the Crown Prince Maha Vajiralongkorn.
The King's body and his family will then travel by motorcade to the Grand Palace, where mourners have already begun to claim spaces to watch the historic event. Many have been camped out as early as midnight.
"I couldn't sleep and I didn't want to sit around at home, I had to do something as I was feeling so sad," says Patarapong Chankaw, 28. "So I came to the grand palace to be with other mourners."
He's been at the Grand Palace since 5 a.m. local time and plans to stay until the procession is over.
Once the body arrives at the palace, it will undergo a funeral bathing ceremony -- a traditional rite in Buddhist culture.
Thais have also lined up for the opportunity to pour water on a portrait of the King inside the palace grounds -- a way for the masses to simulate the symbolic royal bathing of the King's body.
"This is an important moment in my country's history," said 36-year-old Anon Pairot, who was one of those that attended the public gathering.
"I wanted to be a part of it and join other Thais as we mourn our King."
The sun rises without a King
As dawn broke Friday, the streets were awash with grief as the reality of the Thursday evening passing of the King began to set in.
The tide of pink and yellow of the past few days, worn as a show of support for his majesty, has now made way for a sea of black.
Friday has been declared a public holiday for government offices by the Thai cabinet, according to an announcement on state television.
Some of the normally bustling streets of Bangkok were quiet as somber Thais set out on their morning commutes.
On Bangkok's Skytrains, digital screens which normally show loud advertisements were turned off.
But Bangkok is carrying on with its regular routines as much as possible.
Many businesses are operating as normal -- the public holiday is discretionary for private companies. Open restaurants have their televisions tuned to royal documentaries, which are airing on all channels.
Crown Prince Maha Vajiralongkorn was appointed the King's successor in 1972, but exactly when
the Crown Prince will ascend to the throne is yet to be announced.
Thai Prime Minister Prayut Chan-o-cha said "he needs time to jointly mourn with Thai people."
According to a palace statement, all government buildings will fly the Thai flag at half-staff for 30 days starting October 14, and all civil servants have been ordered to wear black clothing for a year as a sign of mourning.
The Thai cabinet is also asking the public not to hold any "entertainment activities" for a month, according to an announcement on state TV.
He urged citizens to remain calm, for the sake of the country's stability, and said soldiers would be stationed in "every area throughout the kingdom" to boost security in preparation for the funeral.
A people shattered
Hundreds of people had for days gathered at Bangkok's Siriraj Hospital where the king was being treated, and as the sun began to set, the crowd swelled into the thousands.
They were dressed predominantly in pink -- an auspicious color Thais believe will restore health -- and yellow, the color of the King.
Some outside the hospital said they didn't know where else to go for comfort, and many said they had hoped he would live to 120.
The huge lines remained Friday, as mourners waited for ferries to cross the river and visit the hospital.
Nearby Charoen Krung Road, one of the city's oldest thoroughfares, was packed with mourners.
Janet Osbourne, who was visiting Bangkok from the UK, told CNN she thought the scene was "remarkable to witness."
"It's quite sad to see, clearly the people of Thailand had so much respect for their king," she said. "As as tourist, I think it's important to respect the nation as it grieves."
Also known as Rama IX -- a reference to his lineage stretching from Rama I, the founder of the Chakri dynasty -- Bhumibol commanded great love and respect within Thailand. An energetic public relations machine promoted his popularity, which led to his portrait being adorned with marigolds everwhere in Thailand, from Bangkok office lobbies to the poorest of rural homes.
Many in the crowd carried those same photos. They prayed and sang the royal anthem and repeatedly shouted, "Long live the king."