Which, of course, was only weeks before the terrorist attacks on Sept. 11. Since then, the Port Authority has dived back into real estate, pouring at least $7.7 billion rebuilding the area around Ground Zero. Some of that money went for the 9/11 memorial and museum. But some $4 billion went to an over-the-top PATH station. And another $3.3 billion has gone to build One World Trade Center — which used to be known as Freedom Tower, and, at a symbolic 1,776 feet high, is now the tallest building in the country.

Whether or not building commercial skyscrapers was the right way to rebuild Ground Zero, what can be said for sure is that the Port Authority has shown, yet again, that it doesn’t belong in the real estate business. One World Trade Center is the most expensive high-rise building ever built in America, and it is costing the Port Authority a fortune. Only 55 percent of its 2.6 million square feet has been leased, and most of that is at a significant loss. Meanwhile, 4 World Trade Center, which was developed by Silverstein, has only 60 percent of its space leased. As The Wall Street Journal pointed out recently, between the two buildings, there is more than 2.5 million square feet of unleased space at Ground Zero.

So why in the world would the Port Authority be willing to back another $1.2 billion in loans to help Silverstein build 3 World Trade Center? Yet on Wednesday, that is exactly what the Port Authority board is supposed to vote on.

Silverstein needs the loan guarantee for a simple reason: The market is saying that, with all that empty office space, this is not the time to be building another skyscraper downtown. He has, so far, found one tenant, but banks are insisting that a higher percentage of the building be preleased before the construction of the building will get financing. So Silverstein has turned to the Port Authority instead to be his funder of last resort.

And not all that long ago, it would have been a safe bet that the Port Authority would have gone along. Indeed, the vice chairman of the board, Scott Rechler — a realtor himself — has said that “it’s part of our mission to finish it.”