"Either jump or die," Mr Nguyen Trong Phuc told himself on turning around to see a blaze sweeping through the window of the restroom he was standing inside.

From the restroom's ventilator window, he tried to see where the metal roof of the house next door was, and then he jumped. That decision saved his life.

Mr Phuc is one of the 30 survivors of a deadly fire at the An Phu karaoke parlour in the southern province of Binh Duong. That fire was the deadliest to occur in Vietnam in the past 20 years.

Mr Phuc started his night shift at the karaoke parlour at 6pm on Sept 6. The 18-year-old was new to the place, having worked at the parlour in Thuan An town, about 50km from Ho Chi Minh City, for less than a month.

An Phu was one of the most popular venues for partying in Thuan An. It had a floor area of more than 1,500 sq m over three storeys. On the evening of Sept 6, Mr Phuc received the first group of customers soon after he started his shift.

"Most of them were already quite drunk when they got there," he recalled.

That night, everything was "normal", with customers singing and dancing passionately and some rooms ordering a second carton of beer. Soon, that normality was broken rudely with the sound of someone screaming, Mr Phuc said.

"Smoke! There's fire in the room," two customers screamed as they rushed out of room No. 303 and ran downstairs.

Mr Phuc and another male employee went in to inspect the situation, but "we were hit in the face by the smoke even though the fire could not be seen".

By then, black smoke was also rising along the two staircases leading to the third floor. Mr Phuc yelled into his walkie-talkie: "Anyone there? There's fire up here!"

There was no response, only screams and chaotic sounds.

By that time, the second floor was engulfed in flames, completely cutting off the third floor from the rest of the building. Mr Phuc and the other male employee knocked on the doors of rooms on the third floor and tried to scream as loudly as possible to alert people to the fire, but the customers kept singing.

The power was cut shortly after, leaving the entire parlour dark and filled with smoke. Mr Phuc tried to reach the staircase in an attempt to go downstairs, but the smoke was suffocating.

He went into an unoccupied room on the third floor, entered the restroom and shut the door to escape the smoke. He washed his face to compose himself and then rushed back out, only to see that the flames had grown even stronger and were about to spread to the restroom. He made a quick decision: take a risk and jump down.

Standing on the toilet, he climbed through the ventilator window and jumped down from a height of around 10m. He fell onto the metal roof of the house next to the parlour, breaking his right leg in the process.

At 8.40pm, firefighting trucks from the Thuan An police department arrived to rescue people and put the flames out.

At the site, the flames were raging all over the building. Black columns of smog and fumes spread around the premises, threatening anyone who dared to get too close.

Firefighters spent the entire night trying to put out the flames. Twelve hours after the fire had broken out, smoke was still emerging from the roof and through holes in the walls. Ambulances came and went constantly and the number of casualties kept going up by the hour. The search for victims lasted 23 hours. A total of 32 bodies were found.

It was the deadliest fire in Vietnam in 20 years since a fire at the ITC building in Ho Chi Minh City claimed the lives of 60 people in October 2002.

• This story was first published by VnExpress International in September.