Sri Lanka's economic crisis came to a head on the weekend when protesters stormed the presidential palace and set fire to the prime ministerial residence.

It forced an announcement of resignation from President Gotabaya Rajapaksa and Prime Minister Ranil Wickremesinghe.

The unrest was the culmination of an economic meltdown that's led to shortages of essential items like food, fuel and medicine, with the prime minister warning the economy is headed for "rock bottom".

Food supply is so dire, government workers were given an extra day off for three months so they had time to grow their own food.

Fuel has all but run out — schools had to be closed because there wasn't enough fuel for teachers and parents to get children to classrooms.

Nationwide power cuts of up to three hours a day were imposed because they can't supply enough fuel to power-generating stations.

Doctors have resorted to appealing on social media for critical supplies of equipment and medicine.

And Sri Lanka is hurtling towards bankruptcy, with hardly any money to import gas, milk or even toilet paper.

People are suffering, desperate for things to improve.

On Saturday, that desperation reached boiling point.

Scroll slowly and watch the video to see how it unfolded.

Thousands of protesters entered Sri Lanka's capital Colombo and swarmed the President's fortified residence.

They wanted a solution to the economic crisis gripping the country. They wanted the President to resign.

The crowd was so large it surged past armed guards and into the palace.

Live video broadcast on Facebook by a local news outlet showed protesters inside the residence packing rooms and corridors.

They chanted slogans demanding Mr Rajapaksa resign from the presidency.

The President was not there at the time. Officials said he left on July 8 as a safety precaution.

Hundreds of people milled about in the grounds of the colonial-era residence, with few security personnel in sight.

Protesters walked through the massive halls, witnessing first-hand the opulence of the President's residence. 

Chanuka Hayasuriya, a 32-year-old businessman, said the luxury he'd witnessed was too much.

"When you see the luxuries in this house, it is obvious that they don't have time to work for the country," he said.

"I think even for the new person who comes [to power], these luxuries are too much.

"A small place must be given and that would create the environment for them to work for the country.

"Places like this are a waste of national resources."

The protesters also took the opportunity to explore the grounds.

Many took a dip in the president's swimming pool.

Others stood at the edge of the pool cheering those who swam.

A few kilometres south, protesters were also storming the prime minister's residence.

Soldiers and police couldn't hold back a crowd of chanting protesters demanding Ranil Wickremesinghe resign.

Eyewitness video shows flames engulfing the building.

The Prime Minister's office said the protesters had started the fire.

On Sunday, the fire had been put out and a calm had returned to the streets.

The blackened walls and windows could be seen from the street.

There were no reports of injuries from the blaze and government sources said Mr Wickremesinghe had been moved to a secure location.

By this stage, both the President and Prime Minister had agreed to resign.

And things had calmed down at the President's palace too.

With many of the protesters gone, people and their families took advantage of the opportunity to tour the residence.

Some people wandered around the grounds. 

Some lay on the grass.

Some explored the President's personal gym.

Others lounged on a four-poster bed, taking selfies on their phones to capture the moment.

What happens now?

Sri Lanka's opposition leaders are yet to agree on replacements for the President and Prime Minister, whose residences still remain occupied by protesters.

Just two months after taking office, Prime Minister Wickremesinghe said he would leave office once a new government was in place, and the parliamentary speaker said Mr Rajapaksa would step down from the presidency on Wednesday.

These protests didn't happen out of nowhere — they had been planned for weeks

In June, a group of activists began meeting regularly at a seaside tented camp in Colombo to think up ways to revive Sri Lanka's flagging protest movement.

The movement is referred to as Aragalaya, or the "struggle" in Sinhalese.

The group's aim was to force President Rajapaksa out of office, according to three members.

The Aragalaya group used a mix of old-school and online campaigning methods, distributing leaflets and posting to Facebook and WhatsApp.

Members said it also liaised with political parties, workers unions and students groups to gather a few thousand people in Colombo's district for a final push.

The group chose Saturday, July 9 for the protest because it marked two months since the President's older brother, Mahinda, stepped down as prime minister, and a month after his younger brother and former finance minister, Basil, quit as a politician.

Momentum for the movement began to build.

The group mobilised volunteers across Colombo, particularly middle-class government housing estates, as well as people from towns and cities across the country.

Late on Friday, police declared a curfew in several of Colombo's districts in an effort to stall the protest, which lawyers decried as illegal.

The protests were beyond the group's wildest imaginations

Riding by trains, buses, lorries, bicycles and on foot, hundreds of thousands of people occupied parts of Colombo.

Security forces were vastly outnumbered.

The group's movement had harnessed the widespread anger against the President for plunging Sri Lanka into its worst economic crisis in seven decades.

Within hours of the protesters storming the President's office and official residence, both leaders announced their resignation to allow an all-party interim government to take over.

No sitting Sri Lankan president had ever resigned from office.

"We put all our energies then to inspiring people to set aside whatever problems they have and to make effort and come," activist Ruwanthie de Chickera said.

ABC/Wires