Maputo — One of Maputo's least loved landmarks, the unfinished and derelict "Four Seasons" hotel, disappeared for ever on Saturday morning, brought down in a controlled implosion.

The successful operation, undertaken at precisely 07.00, lasted for just 13 seconds. A sound like a thunderclap could be heard, and the building collapsed upon itself.

It had been thought that a huge cloud of dust would envelop the site, taking half an hour to dissipate - but the torrential rains that fell in Maputo over the past two days ensured that this did not happen.

The demolition used 2,700 kilos of explosives and 988 detonators. These were placed at six points in the 29 storey building (on the ground, first, second, seventh, ninth, 13th, and 22nd floors).

Matt Zaiman, general manager of the American company CDI (Controlled Demolition Inc), which was in charge of destroying the building, said the implosion was highly successful.

Zaiman said that demolishing the "Four Seasons" was one of the most difficult tasks CDI has ever undertaken, since the construction was highly resistant.

Part of the left side of the building was left standing, apparently deliberately, and will be demolished mechanically.

Lopes Pereira, chairperson of the Four Seasons Property Company, which holds the lease on the site, told reporters that the demolition cost 600,000 US dollars. He said the next stage will be to remove the rubble - which will be more expensive (1.2 million dollars) and could take up to five months.

Once the site is clear, new premises for the United States embassy, and a tourism and office complex will be built there.

Pereira said this construction could begin in early 2008.

However, the deal is not entirely done: Pereira said negotiations are still under way between the company and the US embassy.

Security measures were taken, including establishing a temporary "Exclusion Zone" in the vicinity of the "Four Seasons", that people could not enter or leave for two hours. Residents of this area were advised either to leave 45 minutes before the demolition, or to stay indoors with the windows and doors shut.

During this period the Maputo coast road was also closed to traffic.

When designed in the colonial era, the "Four Seasons" was intended to be the grandest hotel in what was then Lourenco Marques. But it turned into a gigantic eyesore towering above the nearby beach.

The original owner was the South African Four Seasons hotel chain. Its plan for a 340 room luxury hotel, with a view over Maputo Bay, was drawn up in 1969.

By 1974, the structure of the hotel was complete, including the plumbing, electricity and sewers. But that year Portuguese colonialism collapsed, and in September the new Portuguese government signed the Mozambican independence agreement with the liberation movement, Frelimo.

The Four Seasons group and their Portuguese partners rapidly lost interest in its Maputo investment, and construction halted.

According to a detailed history of this ruined building, contained in the latest issue of the independent weekly "Savana", bits and pieces of the unfinished hotel, including doors and windows, were sold off, or stolen. So were the cutlery and towels that had already been produced, bearing the Four Seasons logo.

The Minister of Public Works at the time, Julio Carrilho, said the post-independence government had other priorities, and paid little attention to an unfinished hotel. It was also clear that the building work had been shoddy, and the hotel suffered from several technical defects.

A few years late the government decided to turn the building into an "apartment hotel" to accommodate foreign workers, and so construction restarted. Rooms were restructured, introducing kitchenettes. But the money seems to have run out, for construction halted again in 1981.

Since then a series of companies have expressed an interest in the hotel, some even signing agreements with the government, but they have all given up.

Then, in 2004, the new Four Seasons Company was formed. The then Prime Minister, Pascoal Mocumbi, authorised the sale of the derelict hotel to this company.

Initially it looked as if this company, despite the financial muscle of one of the country's major commercial banks, the BCI, would also fail to do anything with the site. Then came the Americans.

"Savana" suggests that the main factor behind the decision to demolish the hotel was the American obsession with security - understandable in the light of the terrorist attacks against US embassies in Kenya and Tanzania, and the 11 September 2001 atrocities against New York and Washington.

The Americans wanted a secure site away from the bustle of central Maputo, and here was a large site beside the beach containing nothing but a large ruin. So rather than the enormous expense involved in trying to rehabilitate a 32 year old shell, the company decided it would make more sense to rent the land to the Americans.

Over the years, urban legends have circulated about the hotel. It is said that fleeing Portuguese settlers poured liquid cement into the plumbing system, or down the lift shafts.

"Savana"'s investigations, however, show that this is just a colourful myth.