A month after fireworks ignited Beijing’s uncompleted, unoccupied Television Cultural Center (TVCC) high-rise, leaving it a charred shell, there are a number of theories about how the fire started and spread. Few are willing to speak on the record, but one developer unconnected to the project has proposed prohibiting the launching of fireworks in densely populated Beijing.

Photo: AP/Wideworld

TVCC shell framed by adjacent CCTV tower.

Adjacent to Rem Koolhaus’s iconic China Central Television (CCTV) headquarters, the new structure burned the night of Feb. 9, the last night of the Chinese New Year’s fete. A firefighter died from smoke inhalation.

Most blame is directed at state-owned CCTV. Beijing authorities detained 17 people, including CCTV’s chief of construction. The Hunan Province-based fireworks company that ignited nearly 700 high-explosive “A-grade” pyrotechnic devices did not have the required municipal approval. Launching the explosive rockets require permitted, trained personnel. “The company did not listen to the police, who advised against setting off A-grade fireworks,” said Luo Yuan, Beijing Fire Control Bureau deputy chief.

Many questions remain about the speed with which the fire spread through the 31-floor, steel-framed building, whose contractor is Beijing Urban Construction Group Co. Ltd. Damage estimates topped $588 million. The TVCC tower is comprised of three structures: a central main tower to house a restaurant and the 241-room, five-star Mandarin Oriental hotel, and two sweeping, angular side wings designed to host a theater, television studio and an electronic data processing center.

How the fireworks penetrated the structure’s cladding isn’t clear. The tower’s northern and southern facades are metal and glass. On the east and west sides, metal strips form the cladding.

According to published reports, firefighters suspect that two fireworks struck the tower’s south side, burned through the thin metal facade and ignited a flammable insulation layer underneath, which then carried the fire over the entire building. Unnamed architects who helped design the CCTV complex suggested a slightly different possibility, according to a report published in Caijing, a Chinese financial publication. After visiting the site and surveying video and photos of the tower burning, they said they “suspect the fireworks set flame to the tower’s exterior at several points. The flames continued from there to the insulation layer underneath, and then inside the building where interior decorations spread them further.”

Another alternative theory, from an architect on TVCC’s design team, suggests that heat transfer alone may have set fire to the building. The structure’s reinforcing bars could have become superheated from the nearby explosions, said the unnamed architect. If they became hot enough they could have kindled the insulation. Beijing fire officials said the fire began on the building’s roof and spread to the lower floors, fed by high winds, while a CNN report posited “there was a lot of debris on site, which ignited very quickly.”

Chimney effects in the hollow core between the fifth and twenty-sixth floors may have accelerated the fire’s spread. Once the fire broke out, the core may have accelerated the burn. Several explosions were seen and heard, according to witnesses. The Beijing Municipal Fire Bureau also confirmed TVCC’s core collapsed in the fire.

TVCC had followed all city building codes, which include leaving the sprinkler system unpressurized during construction, according to Aaron DeWoskin, an architect at Huatong Design & Consulting Engineering, an expediter for registration and city ordinances for construction and engineering projects in Beijing.

Members of the design team—Rotterdam-based Office for Metropolitan Architecture and Arup East Asia, the local branch of the British design and engineering firm—did not respond to calls or e-mails. Nor did Mandarin Oriental, which is responsible for managing the hotel property. All plan to announce updates in the future. At this point, none have said whether the building will be torn down or if renovations will commence on the standing skeleton.

The building was scheduled to open in mid-May and the hotel, which had been insured for $220 million, this summer. It is not known if the official inauguration of the new CCTV tower, slated for October, will be postponed, nor the value of insurance payouts, which depend on the outcome of an ongoing investigation.