A fire that raged through a mattress factory killed 55 people and injured as many as 24 others in the Moroccan city of Casablanca , officials said, the Associated Press reports.

It seems that the workers were trapped inside, as the emergency exit was blocked. The firefighters arrived two hours after the blaze began at about 10 a.m., the head of the Red Crescent rescue operation declared.

“I don't think we realized how big the fire was,” the Red Crescent official, Jawad el-Mejdoubi, said in the emergency ward of Ibn Rochd Hospital. “Twisted bodies, faces disfigured by fire,” he added.

Angry crowds outside the building accused the factory’s owner of blocking the doors and the emergency exit.

“The plant's owner, Adil Moufarreh, and his son Abdelali Moufarreh, who was the manager, have been taken into custody after having been questioned by police,” officials said at the scene of the disaster, quoted by Agence France Presse.

According to the MAP news agency, an investigation regarding the cause of the blaze would also examine security measures and work conditions at the factory.

Firefighters said many workers were trapped in the spiral stairwell of the building. One of the victims, a 29-year-old woman who managed to escape, claimed many deaths occurred on the third floor, where women sewed. “We ran to the door. It was blocked, to the elevator, it was blocked. Then, oops, the lights went out,” Rachida Darif told the A.P.

Nearly 100 people were in the factory when the blaze burst out. Fire officials declared 55 people were killed, 21 women, 28 men and several others whose bodies were too charred to identify their sex.