Reports from the Hanoi Police said the fire broke out at about 1 am on May 24 at a house in a small lane on Trung Kinh Street.
A 50-member fire rescue team arrived at the site 10 minutes later when the fire had spread over the house and its yard, burning bikes and motorbikes parked here.
Rescue workers saved seven people, including three with injuries from the fire.
The fire was brought under control at 1.26 am, with 14 bodies found in the debris.
The police said the building had five floors, and each floor had two apartments for rent. The first floor was used as an electric bike repair shop.
Nguyen Van Nhan, 61, who lives next to the building said that loud explosions and screams for help woke him at around 1 am.
"I rushed out to see the fire spreading out," Nhan said. "I brought some buckets and joined some locals to try to put down the fire using water. Some others managed to break the gate and climb up the building's outside wall using ropes and successfully save the house owner, his daughter-in-law and his two grandchildren before the fire fighters arrived."
Deputy Ministers of Public Security Nguyen Van Long and Tran Quoc To arrived at the site at 6 am to observe the rescue work.
Deputy Prime Minister Tran Hong Ha and Hanoi Chairman Tran Sy Thanh also appeared at the site.
Police are investigating the cause of the fire.
