Egypt's 40 million Moslems are observing the holy month of Ramadan this year in an unusually sober mood following a spate of disasters that has reminded everyone of the precarious state of the country's underpinnings beneath the new veneer of prosperity.

The three weeks before the dawn-to-dusk fasting began June 11 brought two serious train crashes, the most disastrous boat fire in the contemporary history of the nation and the evacuation of 180 families in an upper-class Cairo suburb because of the threatened collapse of a new 17-story apartment building.

At least 350 persons died in the three accidents and hundreds of other lives were jeopardized. But these were not isolated incidents; they were the culmination of a long series of mishaps over the past year that have included train crashes, collapsing buildings and burst sewer and water mains flooding entire suburbs of Cairo. Between 65 and 75 Egyptians have died this year in old and new houses that have come tumbling down.

Behind this streak of "accidents" is a long story of neglect, indifference and corrupt practices that have come to be associated in the public mind here either with the general decrepitude of Egypt's antiquated facilities or the abuses of its new prosperity under the free-wheeling "open door" economic policy.

It has long been an assumption, although unstated, that nothing can be done about whatever happens because of the "advanced" age of the country's facilities--roads, buildings, wiring, sewers and water pipes--and the hopelessly overcrowded conditions of the cities.

But with the growing number of man-caused disasters befalling the country, this traditional mood of acceptance has begun to give way to a new mood of public outrage and questioning.

The change has been reflected in the tone of newspaper editorials such as appeared in the English-language Egyptian Gazette after the latest train accident June 10, in which at least 24 persons were killed and 47 injured.

"Three major train crashes in as many months constitute not three separate tragedies but one national diasaster," the Gazette said.

Sensing the changing mood, President Hosni Mubarak has given priority to trying to renovate 19th century Cairo, where between 12 million and 14 million people are massed, while constantly reminding Egyptians that he has "no magic wand to wave or button to push" to cure the country's ills overnight.

The worst recent disaster occurred on May 25 when a boat towing two ferries on Lake Nasser in southern Egypt caught fire in the early hours of the morning. In the ensuing pandemonium 317 people either drowned or burned to death.

Who was responsible remains a murky question. The government has arrested all the surviving crew members (three died) and charged them with negligence and manslaughter for abandoning the ship without trying to put out the fire or help the passengers. But crew members have charged that fire extinguishers were empty and lifeboats missing.

In the June 10 railway accident outside Cairo, one train plowed into the back of another that had halted.

Investigation showed the train had stopped because a peddler trying to get off had pulled the emergency cord. Peddlers, it turned out, do this all the time on the line to Upper Egypt and apparently only luck has prevented other accidents.

In an accident 10 days earlier, two trains crashed head-on between Cairo and Alexandria largely, it was reported, because of the lack of communications equipment and signals on the rail line, the main one between Egypt's two largest cities. One engineer simply had no way of knowing the other had stopped his train on the track because six cars had derailed.

While the latest accidents can probably be attributed to negligence and indifference, the story of the brand new 17-floor apartment building, whose supporting pillars began crumbling even before it was inhabited, is an outgrowth of Egypt's economic liberalism and "open door" to private enterprise started in 1974 by the late president Anwar Sadat.

The policy brought with it an apartment-building boom that has given rise to many a scandal involving Egyptian entrepreneurs on the make for quick profits.

These overnight millionaires have often been willing to take shortcuts, bribe officials to get around the building codes, use faulty materials bought on the black market and put up additional stories beyond the approved number. The government estimates there are 3,000 to 4,000 cases of illegal construction in Cairo alone.

In March, a 10-story building in fashionable Heliopolis, the suburb where Mubarak lives, collapsed onto a villa, killing more than 20 persons including the landlord and a deputy minister of tourism. The landlord had built four extra floors and the weight was too much for the pillars.

The apartment building from which more than a hundred families have been evacuated is in Mohandessin, an upper middle class suburb on the west bank of the Nile. It too has three or four extra stories, but this may not be why 10 of its 104 supporting pillars have cracked apart.

Initial reports strongly suggest that the iron bars used to reinforce the cement in the building are defective.

Police have evacuated 180 families from 16 nearby structures, leaving a ghostly silhouette of an empty tower as witness to the building practices that have become common in Egypt.