According to a report from local authorities, the fire broke out at the 400-square metre mattress production factory of Ngo Tien Hanh in Quang Xuong District at 8.30 am.
The fire quickly spread to the adjacent two-storey house of Hanh's brother, Ngo Tien Thu, who also used the first floor to produce and store mattresses.
There were four people in Thu's house at that time and three managed to flee. Meanwhile, Thu's daughter, Ngo Thi Lan Anh, 20, was stuck inside a restroom on the second floor.
A witness said that many residents had tried to put out the fire but it spread so quickly with smoke rising up to 40-50 metres high.
The fire had spread all over the two facilities when firefighters arrived 30 minutes later.
The fire was properly put under control at 9.30 am when rescue forces accessed Lan Anh. However, she died on the way to hospital.
Authorities are investigating the cause of the fire.
