MOSCOW (AP) — Russian authorities were reportedly warned back in 1998 that Siberia's massive Sayano-Shushenskaya hydroelectric power plant had fallen into serious neglect and was unsafe.

On Friday, 47 people were confirmed dead and dozens were still missing after an explosion Monday at the plant — an accident that has revealed the dangers of Russia's creaking infrastructure.

For years, the Kremlin was urged by independent experts and even its own ministries to invest some of its oil-and-gas billions to update Soviet-era infrastructure.

But a lack of expertise combined with government apathy means that not only Russian power plants but dangerous roads, decaying utilities, aging transport fleets and creaking buildings continue to take victims as they fall further into disrepair.

Prime Minister Vladimir Putin, who toured the crippled Siberian power plant on Friday, has acknowledged that Russia must plan for the regular upgrade of "vital parts of infrastructure."

But Vladimir Tikhomirov, chief economist at the Moscow-based bank UralSib, says Russia has to spend big if it wants to reverse the neglect of the stagnant 1990s.

"It's about more than $100 (billion) to 200 billion if we're talking about all infrastructure — and you can't make it all in one year," he said Friday.

The latest statistics show that as little as 7.4 per cent of all equipment in the power sector was replaced by 2007. Studies showed that half needed replacing and 15 per cent was worn out beyond repair.

Energy Minister Sergei Shmatko has said it would cost 40 billion rubles ($1.2 billion) just to rebuild the damaged turbine room.

The death toll at Sayano-Shushenskaya is likely to rise with 28 workers still missing and Putin on Friday urged RusHydro, the owner of Sayano-Shushenskaya, to compensate the families of the dead. RusHydro has already pledged to pay 1 million rubles ($31,300) to the families of the dead. Putin promised to match the company's payouts with federal money.

The Emergency Situations Ministry — whose 1,000-strong search team kept up the search Friday for those feared dead — warned back in 1998 that the dam had fallen into dangerous neglect, according to a report by the business daily Kommersant.

The same ministry forecast in 2005 that decaying infrastructure would be the cause of most technological accidents in the coming years, saying more than 60 per cent of Russia's water pipes, sewage, heating and electricity networks needed urgent replacement.

Even Putin accepted in December that 80 per cent of Russia's heating network needed repairs — a critical issue for a nation with such severe winter weather.

Most signs of poor maintenance, however, fail to engage local Russian officials.

Ordinary Russians have endured thousands of low-profile gas explosions in homes, road accidents involving 30-year-old buses and frequent electricity blackouts.

Gas blasts in particular highlight the nation's infrastructure problem. Many Russians in residential buildings that aren't rigged for cooking gas use old, high-pressure canisters. Those frequently burst, killing anyone nearby and sometimes levelling buildings. The damage is compounded by buildings that are not structurally sound and overall poor fire-safety standards.

Short-circuits account for a significant number of fires, emergency officials say.

The global economic downturn has thwarted efforts to finance infrastructure upgrades, such as a now-postponed liberalization in energy sector prices that was supposed to allow privatized power plants to generate enough cash to pay for maintenance and new equipment.

Fearing popular discontent, Russian officials have kept energy costs low — but they might have to shift that strategy.

"The federal budget is not going to have the money to adequately invest in those companies' operations program, so the cost will have to be passed on to the consumers — individuals or companies," Tikhomirov said. "There's no other way, otherwise we'll be in for other technology-caused disasters."