U.S. financial markets have come to a standstill after two planes crashed into the World Trade Center, causing the collapse of the twin towers. All U.S. stock markets will remain closed for the day, says the U.S. Securities and Exchange Commission.

Floor traders have been evacuated the “Big Board,” the biggest stock market, at 11 Wall Street, about half-a-mile from the World Trade Center in lower Manhattan. American Express Co. and Lehman Brothers Holdings Inc. employees have evacuated their headquarters at the World Financial Center – across the street from the World Trade Center. The MetLife Inc. building at 200 Park Ave. has been evacuated, too.

From 150,000 to 200,000 people pass through the World Trade Center complex each work-weekday. That includes 40,000 who work there and 50,000 taking the PATH trains that connect New York and New Jersey, according to the Port Authority of New York and New Jersey.

Morgan Stanley Dean Witter & Co., the largest tenant in the trade center, occupies 12.5% of the twin towers. The south tower was the headquarters for Morgan Stanley’s retail businesses. “We have no information beyond what has been reported in the news,” says the company. “The safety and well-being of Morgan Stanley employees are paramount at this time. We are working with local authorities, and we will keep you apprised of developments.”

The total size of the twin towers was 1,114,800 square meters. Each tower had 43,600 windows. It represented 10% of downtown office space.

Following is a partial list of World Trade Center tenants:

  1. Anthony Ondo & Co.
  2. Paul Liubicich & Commodities
  3. Wako Secuities America Inc.Yamatane Securities America
  4. Keefe Bruyette & Woods Inc.
  5. Commerzbank Capital Markets
  6. Cantor Fitzgerald Inc.
  7. Dean Witter Reynolds Inc.
  8. Brenner Corporate Finance Dept.
  9. Farmers Union Control Exchange
  10. China International Trust
  11. John W. Loofbourrow Assoc. Inc.
  12. Dapco Ltd.
  13. Meyers Pollok Robbins Inc.
  14. Sun Hung Kai Securities
  15. Sterling Commodities Corp.
  16. Jospeh Russo & Co.
  17. Max Gregorcic
  18. GJB Trading
  19. C. Allen & Co.
  20. Grigsby Brandford & Co.

A spokeswoman for CIBC World Markets in Toronto says the Canadian company’s more than 1,000 employees in Manhattan were apparently safe. The brokerage has offices one block away from the World Trade Center.

John Hancock Tower in Boston is being evacuated, says a spokesman for John Hancock Financial Services.