Yesterday?s towering blaze was caused by a ?catastrophic failure? in the Belco power plant?s transmission system, chief executive Garry Madeiros said yesterday.

Mr. Madeiros warned, however, that until a more lengthy investigation of the site is complete, they would not be able to pin down with absolute certainty what specific fault caused the damage ? expected to cost roughly $10 million.

?We did not plan for this kind of catastrophe,? Belco?s chief operations officer Vince Ingham said at yesterday?s afternoon Press conference, before denying the accident had been caused by any excessive demand on the system. ?This is the worst case scenario,? he said.

While any explanation of exactly what started the fire is far from straightforward, the problem seems to have occurred after a fault on the transmission board itself was not cleared by the relevant safety switch ? resulting in a massive build-up of energy behind the blockage which ultimately caused the initial explosion.

Explaining the technical process in layman?s terms, Mr. Ingham compared what happened to a switch not activating in a normal, household fuse-box ? except on a far larger and more dangerous scale.

Why the switch did not perform its job properly was not a question Mr. Ingham was able to answer, although he and Mr. Madeiros were quick to point out that every system will not work ?as it should? from time to time.

?Systems have faults all the time and ours is no exception,? Mr. Ingham said.

?But this is what you would call a real exception. NASA for instance has a similar problem from time to time these systems do not function. In this case, we are fairly certain that our protection system, which normally would have cleared the switch, did not clear the switch in a timely manner.?

Belco normally has five largely interconnected boards that take in energy created from the power plant and then transmit it to users.

However, the board which caught fire was completely destroyed while one other nearby was also ?compromised? by heat and smoke.

Left with only three boards, Belco was forced to scramble frantically last night to bypass the break in the system, and work out a way in which power could be distributed to all parts of the Island.

While the two boards which service the Island?s extremities were already connected, the third took a number of hours to incorporate into the system ? explaining why power was restored more quickly to the eastern and western parishes while central areas, including Hamilton, went unattended until late in the evening.

?Through the process of excavating cables and redirecting power we believe that perhaps in the next 48 to 72 hours we will have a system that certainly won?t be as robust as the system we started with earlier today but will be a system that will be much stronger than the one we are currently attempting to manage,? Mr. Ingham said.

Above all, the need for people to conserve as much energy as possible was a theme which was continually stressed. ?The lower our load is, the better the chance of supporting that load,? Mr. Madeiros said.

?When people do eventually get power, they should only use it on things that are essential and not on every possible thing they can.?

Businesses with generators were also encouraged to continue using them today to give Belco ?a cushion?.

Mr. Ingham said it would take 12 to 18 months to completely replace the switchboard, not to mention the building in which it was stored. ?It?s not like you can get these switchboards down at Wal-Mart ? they are highly specialised and complex pieces of equipment,? he quipped.

But in the meantime, Belco is looking at establishing a mobile-type switchboard until a brand new one is ordered and installed.

Pressed on whether he could guarantee no more incidents such as yesterday?s fire would happen again in the near future, Mr. Madeiros said it would be ?foolhardy? to say there was no risk, but added he was confident that all the steps had been taken to prevent it.

Potential air pollution was also being monitored by air quality testers, Mr. Ingham concluded, although he admitted that a certain amount of spillage from the oil-coated switches did take place.

Samples were taken to ensure no harmful toxins were released into the water supply or the nearby canal, and so far, results have been encouraging.

Meanwhile, Fire Service spokesman Dana Lovell revealed that a claims adjuster from insurance giants Lloyd?s of London is being flown in to inspect the damage.