By Quentin Sommerville
BBC News, Beijing
The charred hotel tower is visible to the right of the CCTV building
Spectacular explosions over Beijing heralded the end of the lunar new year celebrations.
But as the fireworks rose and fell, a new landmark building caught fire.
Parts of the building, which included the unfinished headquarters of state broadcaster China Central Television (CCTV), were quickly overwhelmed by flames.
Days later the damage can be seen from across the city, and fresh details have emerged as to what happened.
Officials from CCTV were using the new building - all sharp angles and gravity-defying engineering - as the backdrop for an illegal pyrotechnics display.
They had bought the biggest fireworks they could get their hands on. At some point, one or more fireworks hit the hotel tower, which also houses a cultural centre. It was still under construction, so the sprinkler system was not switched on.
Now it stands blackened and ruined. The windows in the five-star hotel which took up part of the building are cracked and gaping. The entire 33-storey block may have to come down.
Beijing's fire chief said the state broadcaster did not have permission for such an elaborate display.
"They set off the fireworks at the south-west end of the building. That is pretty close to the building, maybe a dozen metres [40 feet] away. At that time, everyone was setting off fireworks - the same ones used for the Olympics, ones that are set off by computers.
"These are considered category 'A' fireworks. In Beijing you must get permission from the local government to set off such fireworks," he said.
CCTV had not obtained that permission. Worse still, as foreign ministry spokeswoman Jiang Yu pointed out, staff had been warned not to set off the powerful pyrotechnics.
"According to the initial investigation, the fire was caused when officials didn't listen to police warnings, they persistently and illegally set off fireworks. The precise cause of the accident is still being investigated," she told a briefing earlier this week.
The CCTV site has always drawn stares. But now it is more of a tourist attraction than ever before.
"Even though the government spent money, this was a good building for ordinary people," said Wang Yu Yin, who came to take photographs to send to friends outside of Beijing.
The blackened ruins of the hotel have now become a draw for sightseers
"It's like the Bird's Nest [Olympic stadium]. It has become a tourist hotspot and Beijingers are proud of it. It is the same with this CCTV structure. I feel so sorry that this happened."
As the building burned, people rushed to see it, and began posting pictures on websites - but some of those images were initially removed.
Later, as details emerged that it was its own staff who had accidently burned down the building, CCTV issued a rare apology.
"The fire caused serious damage to the state property, and CCTV is deeply remorseful. It also brought inconvenience to the people living nearby and caused traffic jams, and CCTV expresses sincere apologies," a presenter said.
But many find that response unsatisfactory. CCTV may be powerful, and well funded, but the government's propaganda mouthpiece is not held in high regard.
The main CCTV building is known as the "giant underpants". Soon insults began appearing on websites: "Liar, liar, pants on fire."
CCTV's apology made no mention of the fireman who died, or the six others injured fighting the flames. Since then it has said very little.
But other parts of the state media have not been so quiet, and have warned of likely prosecutions.
On Thursday 12 people - including a CCTV official - were detained in connection with the fire.