A clip showing victims of the Mountain B pub fire running through the front door has raised questions over whether the nightspot had a fire exit, while a singer at the pub wrote on Facebook there was only one way in and out for customers.
The singer, who goes by the name "Nui Voice Raphon", posted on Facebook that the pub's single main entrance/exit had always troubled him as it is quite narrow.
He also wrote that the back door, which is normally used by musicians, is kept locked and the key given to a supervisor. When musicians arrive, they must ask the supervisor to unlock the back door, which is closed as soon as they are inside.
According to the singer, whose band played at Mountain B every Monday, the stage where the bands play is far from the exit and the pub ceiling is lined with sound-absorbent materials that are highly flammable.
"Of course when the fire broke out, the flammable materials made it spread fast. The place was crowded and the customers were drunk. Some escaped while some stumbled at the door and blocked the exit."
As authorities sorted through evidence in search of the fire's cause, a witness told police that they heard two explosions near the disc jockey's booth and confirmed that sound-absorbent materials caught sparks and helped the fire spread.
Thanyapat Sornsuwanhiran, a 26-year-old employee, said the fire started in the ceiling. She told security guards to help customers leave through the front door.
However, the blaze spread quickly.
A rescue worker, who was among the first to arrive at the scene, said the flames were over five metres high and people were rushing through the front door.
Some incurred burns and suffered from smoke inhalation, while others were injured in the crush at the exit.
Thirteen people were found dead inside the venue; one victim died later in hospital.