By now you will have seen too many pictures and read too many words and yet, as the new week dawns, it still remains too horrible to believe.

Thousands of dead.

Incomparable devastation.

The nation at war, whether officially declared or not.

And now, the strong likelihood of an economic ripple effect that will leave Los Angeles and the rest of the nation with a long-feared recession one that might be longer and sharper than earlier envisioned.

Of course, no one really knows, since last week’s terrorist attacks destroyed or damaged so much of the nation’s financial nerve center. From a business standpoint, that makes the effects unprecedented in scope far beyond the Gulf War, far beyond Vietnam and Korea. Even the Japanese during World War II could not have conceived of bombing New York and Washington.

The first and most worrisome question this week is what happens with the stock markets, which will finally resume trading on Monday. The early hours are certain to be rocky perhaps far worse since nearly a full week will have gone by since trading was suspended and it’s almost certain that pent-up sell orders will drive down prices.

After that, opinion is mixed on whether the markets are close to hitting bottom or destined to keep going down for countless weeks and months.

And what of the economy? Consumers are not likely to be buying cars or houses in the coming days, but how long will that funk last? Days or months?

“This is completely uncharted territory,” admitted Jack Kyser, chief economist of the Economic Development Corp. of Los Angeles County, who estimated last week that Los Angeles lost $200 million of its $1 billion-a-day economy on Sept. 11, the day of the attack. Estimates of the national losses run upwards of $200 billion, but as with any disaster, early numbers are more guesstimates.

So are the longer-term prospects. The consensus seems to be that it will take at least a month for L.A.’s economy to return to pre-attack levels. Still, economists have few precedents to guide them, not only because of the scope of the calamity but because disasters often unfold in unexpected economic ways.

The 1994 Northridge earthquake resulted in losses of hundreds of millions of dollars and at a time when the area already was suffering from a three-year recession. Yet the disaster brought a multi-billion dollar infusion of government and insurance money that generated new business and revitalized the local economy.

The 1941 attack on Pearl Harbor was a terrible blow to the nation’s psyche and resulted in a massive loss of life, but it helped transform Los Angeles’ budding aerospace industry into a major defense locus.

“I don’t think this is like anything that L.A. has ever seen,” said Don Straszheim, vice chairman of the Milken Institute in Santa Monica. “This would not have turned a robust economy into a recession. It will likely cause some short-term damage, but this too will pass.”

Not soon enough for folks like Neil Mitchell, director of World Net International, an Inglewood express-delivery service. Business stopped cold last week when the nation’s air traffic system shut down, costing his company tens of thousands of dollars. “All I am trying to do is figure out what to tell my customers,” he said.

Looking beyond the coming few days, Mitchell wondered how long it would take Morgan Stanley Dean Witter to get back in operation an important consideration since World Net handled interoffice mail drops between L.A. and the World Trade Center, where Morgan Stanley occupied 19 floors. “That’s a sizable account,” he said.

World Net is vulnerable in other ways. It transports film between shooting locations around the world and production facilities in Los Angeles. “This could be something that takes weeks or months to get back to normal,” he said of last week’s travel delays. That could mean layoffs among World Net’s staff of 25.

The worst fear is a slow, stutter-step recovery. “There’s a noticeable slowing in order rates and transactions because everybody’s taking time to reflect on the event,” said Jim Swartwout, chairman and chief executive of Summa Industries, a manufacturer of plastic components in Torrance. Still, Swartwout doesn’t expect a lasting impact.

For now the prevailing wisdom is the most conventional: Travel and tourism face the sharpest cuts similar to what happened after the Gulf War. Other local trouble spots: retail and manufacturing. The aerospace industry is likely to fare well, though to what extent is unclear.

“It’s going to be interesting,” said Peter Griffith, president and chief executive of Ernst & Young Corporate Finance LLC.