The Dow suffered its worst percentage loss in more than six years Monday as the markets were slammed by an historic weekend that left Wall Street without financial giants Lehman Brothers and Merrill Lynch. 

The momentous selloff came as insurance giant AIG lost more than half its value and crude oil futures plunged more than $5, closing below $100 a barrel for the first time since March. 

Today's Market

The Dow Jones Industrial Average fell 504.48 points, or 4.42% to 10917.51, the Standard & Poor’s 500 lost 58.17 points, or 4.65%, to 1193.53 and the Nasdaq Composite slid 81.36 points, or 3.60%, to 2179.91. The FOX 50 dropped 39.47 points, or 4.37%, to 863.37.

The losses brought the Dow below the psychologically-important 11,000 threshold for the first time since July 16. It was the index's sixth-largest point decline ever and the biggest since the aftermath of the Sept. 11, 2001 terrorist attacks.

The markets went into a tailspin in the final minutes of the day, reflecting anxiety over AIG (AIG), Tuesday's Federal Reserve policy meeting and an upcoming earnings statement from Goldman Sachs (GS). The VIX, a measure of market volatility, jumped 23.5% to 31.7 on Monday.

“This is a very bad situation and people are justifiably concerned," said Michael James, senior equity trader at Wedbush Morgan Securities in Los Angeles. “Right now it's sell first and ask question later.”

AIG (AIG) closed 61% lower as Wall Street continues to fear for the insurer's mortgage-related losses and liquidity situation. Bank of America (BAC) dove more than 20% after unveiling an unexpected $50 billion bid to acquire financial powerhouse Merrill Lynch (MER). AIG and BofA combined to account for almost 120 points of the selloff on the Dow. Coca-Cola (KO) was the lone Dow stock that managed to close in positive territory. 

The $639B Bankruptcy

Wall Street emerged from the weekend in crisis mode and with a completely reshaped financial sector. At the forefront of the crisis is Lehman Brothers (LEH), which after 158 years in business filed for Chapter 11 bankruptcy protection as it becomes the latest victim of the credit crisis. Valued at $639 billion, Lehman's is the largest bankruptcy filing in U.S. history -- easily surpassing the collapses of Enron and WorldCom combined.

The demise of the nation's fourth-largest investment bank comes after potential suitors, namely Barclays (BCS) and Bank of America (BAC), pulled out of negotiations over the weekend. The federal government resisted calls to offer the same kind of financial assistance offered when JPMorgan Chase (JPM) bought Bear Stearns in a fire sale in March. Lehman, whose shares hit 52-week highs of $67 last November, closed at 21 cents on Monday. 

“The immediate response is this is a worst-case scenario” or very close to one, said Art Hogan, chief market strategist at Jeffries & Co. “Lehman not being able to find a buyer is startling, if not scary.” 

While Lehman filed for bankruptcy protection with the U.S. Bankruptcy Court of the Southern District of New York, the company's broker-dealer subsidiary and other parts of its business were not included in the filing. The bank said its customers may continue to trade while Lehman winds down its business. 

Lehman has reported a string of massive quarterly losses tied to the investment bank's bad real estate bets. Unable or unwilling to raise cash, Lehman's stock plunged 77% last week as Wall Street began to predict bank's demise.

To help the surviving banks navigate the end of Lehman Brothers, a group of Wall Street banks created a $70 billion lending program to ease a credit shortage. Each of the ten banks, which include Citigroup (C) and Goldman Sachs (GS), committed $7 billion to the pool. 

"As awful as Lehman is, it's not enough to bring down the financial system. It's one step closer to cleansing the system but… the collateral damage will continue to cause a lot of pain through next year," said Peter Boockvar, equity strategist at Miller Tabak. 

Insurer in Turmoil 

AIG (AIG) quickly took over as Wall Street's latest punching bag, seeing its share plummet as it becomes the focal point of the financial crisis. Over the weekend, reports swirled that AIG plans to sell various assets to raise an additional $40 billion to avoid a potentially-fatal credit ratings downgrade. AIG has sought help from the Federal Reserve, the state of New York and even billionaire investor Warren Buffet, according to published reports. 

The selling didn't stop even after The Wall Street Journal reported the federal government has asked JPMorgan Chase (JPM) and Goldman Sachs to lead a $70 billion to $75 billion lending facility for AIG. The Federal Reserve has hired Morgan Stanley (MS) to review the central bank's options regarding AIG, Reuters reported. 

While Reuters reported that Buffett and AIG are no longer in talks, New York state signed off on a deal allowing the insurer to access $20 billion of its policyholders' assets as collateral. New York Gov. David Patterson said AIG is financially sound and that the plans amount to a bridge loan, not a "government bailout."

AIG reportedly rejected a cash infusion from several private-equity firms due to unfavorable terms. AIG has lost $18 billion over the past three quarters as the insurer was slammed by mortgage-related losses. 

Merrill Lynch

Seeking to avoid Lehman's fate, iconic brokerage house Merrill Lynch (MER) agreed to sell itself to Bank of America (BAC) for $29 per share in an all-stock transaction that shocked Wall Street. The deal, which is subject to shareholder and regulatory approval, presently values Merrill at $50 billion. Shares of Merrill soared during intraday trading but closed flat and off by $12 from the offer price.

Merrill has also been slammed by bad bets in the housing market, posting $40 billion in write-downs and credit losses over the past year. The selling price represents a 70% premium from Merrill's close on Friday, though the company's shares plummeted 36% last week to its lowest level in nearly 12 years. 

The bears on Wall Street appeared ready to set their sights on Merrill following Lehman's demise. While CEO John Thain was unable to turn Merrill around and allow it to keep its independence, he was able to make sure shareholders weren't left completely empty-handed. 

Crude Diving

Mostly overshadowed by the turmoil in the financial sector, crude oil plunged as much as $7 Monday morning, closing solidly below $100 a barrel for the first time since March. Crude closed down $5.47 to $95.71 a barrel.

Oil prices have been in free-fall mode since eclipsing $147 a barrel in early July. Crude has been under assault from fears a global economic slowdown will further weaken demand. 

“There is a perception [that] the economic world crumbling around us [has] done more damage to demand than supply," Phil Flynn of Alaron Trading told FOX Business. 

Not surprisingly, energy stocks like Sunoco (SUN) and Valero (VLO) took a nosedive on Monday. The energy sector declined by almost 8% as a group. 

Another Pivotal Day

Tuesday promises to be another huge day on Wall Street as the Federal Reserve is scheduled to make its announcement on interest rates. In a reversal, the markets are now betting there is a 60% chance the central bank will lower interest rates by a quarter of a percentage point. 

Previously, Wall Street had bet the Fed would hold interest rates steady rather than risk fanning inflationary risks. However, over the past several weeks inflation fears have cooled as oil prices have plunged and the turmoil in the financial markets has only worsened. 

Goldman Sachs will take center stage early Tuesday as the financial giant is scheduled to report its quarterly results. 

"Whatever Goldman says tomorrow is far more important than anything the Fed can say," said James, the trader from Wedbush Morgan. If Goldman has anything bad to say, "tomorrow could be very ugly." 

Corporate Movers

Washington Mutual (WM) lost more than one-quarter of its market cap on Monday as Wall Street wonders how the nation's largest savings-and-loan will survive the financial crisis. Analysts at Keefe, Bruyette & Woods predicted WaMu will need to raise up to $5 billion to counter expected credit expenses of $23 billion through 2009. The situation at WaMu comes as CEO Alan Fishman enters his second week after replacing Kerry Killinger. 

Fannie Mae (FNM) and Freddie Mac (FRE) may not be able to give their chief executives "golden parachutes," the Journal reported. The mortgage giants' regulator told the newspaper such severance payment won't be allowed to be made to Daniel Mudd and Richard Syron. Fannie Mae and Freddie Mac, which own or back more than $5 trillion of U.S. mortgages, were seized by the government earlier this month due to fears they would run out of cash.  

General Electric (GE) saw its shares dive to five-year lows on more concerns about the corporate conglomerate’s financial business. GE’s financial-services operations account for almost half of the company’s revenue. There is also growing anxiety over when GE will sell its private-label credit card business.

Electronic Arts (ERTS) ended its marathon efforts to acquire Take-Two Interactive (TTWO), the video game publisher of "Grand Theft Auto." Shares of Take-Two lost one-quarter of their value Monday. EA, which makes "Madden" and other video games, had entered into confidential talks with Take-Two last month after dropping a hostile bid for its rival.

Data Dump

The government said industrial output declined by an unexpectedly steep 1.1% in August, the worst one-month decline since 2005. Economists had been forecasting a more modest 0.3% decline. The Federal Reserve said auto production led the declines, plunging 11.9% last month.

Global Markets

European markets plummeted in reaction to the financial crisis. 

The Dow Jones Euro Stoxx 50, the index that tracks the 50 largest companies in Europe, plunged 126.85 points, or 3.87%, to 3151.17. The FTSE 100, London's benchmark index closed down 212.50 points, or 3.92%, to 5204.20.