The fire that partly destroyed one of the main attractions of the planned Ninth China (Beijing) International Garden Expo might have been caused by illegal hot work, authorities said.

The Beijing Municipal Commission of Housing and Urban-Rural Development said the investigation points to hot work as the cause of the blaze on Monday that destroyed part of the Yongding tower in Beijing's Fengtai district.

Investigators are appraising losses from the fire and drawing up a repair plan, said Gu Xiaoyuan, a publicity officer for the expo.

"Whether the tower will return to its original state is up to the appraisal results, as well as the restoration program," she said.

"However, the expo won't be delayed and will receive its visitors on time."

The tower caught fire at around 3 pm on Monday and was extinguished at about 7:15 pm. A total of 210 firefighters and 54 fire engines were sent to the scene.

No casualties were reported.

The commission released an announcement on Wednesday emphasizing the need to have fire safety inspections at construction sites.

In addition to obtaining government permits for hot work, the sites should also set up temporary fire escapes and suspend work during especially windy weather, the commission said.

Gu said the committee will further enforce construction safety standards and learn lessons from the incident.

Workers at the expo site are putting the finishing touches on preparation for the event, organized by the Ministry of Housing and Urban-Rural Development and Beijing's municipal government.

The expo is expected to run from May to November, with 46 exhibitions from 60 cities.

The event is designed to contribute to the improvement of the city's scenery, as infrastructure projects such as subway stations and roads are being built in the area.

According to Beijing's traffic authority, the western section of the subway's Line 14 will kick off its trial operations on April 14 and open on May 5, in time to serve crowds attending the expo.

The average daily passenger traffic is expected to reach 120,000 rides, and the peak period during the expo might witness a record 200,000 rides a day.

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