But nobody has much bothered about the cracks when officials of the factories forced the workers to join workplaces in the building on the next morning.
Even three days after the tragedy, it is not known exactly how many workers were inside when the building collapsed.
Rescuers reportedly came come up with a list of 761 people who are still unaccounted for.
According to the sources, almost all the death victims are workers of the five factories -- Phantom Apparels, Phantom Tac, Ether Tex, New Wave Style and New Wave Bottoms -- which make clothing for many major global brands.
The building is owned by a leader of Prime Minister Sheikh Hasina's ruling Bangladesh Awami League party who reportedly constructed it without permission from relevant authorities, and assured the owners of the factories that there was no problem despite cracks detected.
Six floors of the building housed the five garment factories which, according to BGMEA, employed nearly 3,500 workers, mostly of them women.
Furthermore, there were also a bank's branch and hundreds of shops inside the building.