A fire swept through a garment workshop building in the southern Beijing suburb Monday morning.

Fire engines were blocked by the area's narrow valleys, and firefighters had to manually carry hoses to the site to douse the blaze, said Wang.

"The first floor was filled with choking fumes. With no way to leave, my wife and I jumped from a platform at the top of the building," said a survivor surnamed Xu who suffered broken legs.

Investigations showed that the building was illegally built by a local resident surnamed Zhang in 2010. Zhang leased out the ground floor to the owners of the garment business.

The floors above the garment shop were rented to migrant workers seeking inexpensive housing. The ground floor also housed the garment workshop's employees.

Forty-three-year-old Gao Defa, owner of the workshop, is also receiving medical treatment. His wife was confirmed dead in the fire. Their 6-year-old daughter is in critical condition.

A further probe into the cause of the fire is under way.

Liu Qi, secretary of the Beijing Municipal Committee of the Communist Party of China, and mayor Guo Jinlong were at the site to direct the investigation.