Mystery Person Leaves $10,000 Cash Donation for 911 Museum

A mystery person has surprised officials of the planned 9/11 memorial and museum with a $10,000 cash donation stuffed into a small Plexiglas donation box.

Along with the expected dollar bills and change in the box at the museum's preview center, someone added 99 100-dollar bills and five 20s. Officials say it's clear the bills were left by a single donor – they were crisp as if right out of a cash machine.

"I was home watching the Yankee game when I got a call from the preview center's manager. She asked me if I was sitting down," Joe Daniels, president of the National September 11 Memorial & Museum, tells the New York Post.

"We just found $10,000 in the donation box," he says he was told.

Some 3,000 people visit the preview center each day. The center outlines plans for the Ground Zero memorial and museum as well as rebuilt World Trade Center, and has artifacts from the Sept. 11, 2001 terrorist attack.

Daniels says officials have no idea who left the donation or why they didn't want a receipt they could use for a tax deduction. He says others have asked to make donations anonymously – including in the seven figures – but they usually write checks.

Some $370 million has been collected for construction and operation of the memorial and museum – including sizable donations from corporations. The museum is scheduled to open in 2012.

But a $10,000 donation with no one taking credit is unprecedented, officials say.

The donation was made during a two-hour evening period, and could have been from any of hundreds of visitors. The 12-by-12-inch donation box hangs on a wall.

Daniels says officials would love to know who left the donation so they can say thanks.