ACCRA, Ghana (AP) — Workers had congregated for morning prayers on the ground floor of the Melcom retail store in northern Accra Wednesday morning at around 9:15 when they heard a "boom, boom, boom" and the five-story building collapsed around them, trapping some 80 people under the rubble and killing at least 17.

"Next thing all I could see was darkness," said Lawrence Darkwah from his hospital bed in Accra Saturday. While lying on the ground in the rubble, Darkwah heard an air-conditioner whirring and moved toward it, on the way coming across a head with long hair. He sat on the air-conditioner in the dark. Like many other survivors he couldn't telephone anyone because he had followed protocol for the prayers and left his phone at the door.

Ghana's National Disaster Management Organization cited structural weakness as the cause of the collapse of the store, which was being leased by Melcom Ltd., Ghana's largest retail chain. Investigations are on-going, officials say.

Rescue workers from the country's police, army and fire service, along with independent contractors and people from the neighborhood rushed to the scene Wednesday morning to search for survivors. The operation was chaotic, with bystanders blocking rescue crews and bulldozers digging into the rubble before it had been checked for bodies.

As a giant excavator tore into a pile of cement and metal wreckage, contractor Daniel Hani yelled: "No, no, no! He has to stop that!" When asked if bodies could be inside, he said, "There could be!"

Darkwah, the survivor, said he saw a crack in one of the building's pillars the day before the collapse, and that he alerted his boss. "I told my branch manager. He later said it was checked and it was just a crack," Darkwah said Saturday.

Vice-president Kwesi Amissah-Arthur declared the collapse a national disaster and Ghana's president John Dramani Mahama interrupted his political campaign for reelection in December to help manage the rescue efforts.

"Whoever is responsible for this negligence ... will pay a price," Mahama told reporters after briefly visiting the site in Accra's working-class Achimota neighborhood.

The president warned "that Ghana being an earthquake prone zone, the likelihood for many buildings of poor quality to go down in case of earthquake is high. We are going to put in place mechanisms to check the safety and security of other high-rise buildings and find out if there aren't any more of such disasters waiting to happen."

Authorities have detained several people following the collapse, including the building's owner, Nana Boadu, and a municipal works official named Carl Henry Clerk, who allegedly knew the building was being constructed without a permit, according to Deputy Information Minister Samuel Ablakwa.

The building's architect and engineer are also being sought by authorities, and one of Melcom's managers was arrested and released on bail, Ablakwa said.

Ghana is undergoing a construction boom driven by record economic growth and authorities say this tragedy highlights the industry's lack of regulation.

"This is a wake-up call to everybody" to upgrade country's building code and enforcement mechanisms, said regional police chief Patrick Timbillah. Continued...