By Josh Ward in Berlin

A surprising number of cracks have been found in Berlin's 2-year-old memorial to Jewish victims of the Holocaust. Germans are asking what is to blame. (AP)

IT WAS hailed as a design that could withstand attacks from neo-Nazis and even graffiti artists. But in the end, the memorial couldn't be protected from the materials used to build it ... or the weather.

An estimated 400 cracks have appeared in the 2,711 concrete slabs of the 2-year-old Holocaust memorial in Berlin.

The memorial, known as the Memorial to the Murdered Jews of Europe, is dedicated to the Jewish victims of the Nazi regime in World War II. It was designed by American architect Peter Eisenman and erected by the firm Geithner Bau from 2003 to 2005 at a cost of ¤10.5 million ($14.5 million).

"It's really not a surprise at all," said a spokesman for the Foundation Memorial to the Murdered Jews of Europe, which oversees the memorial. "We already had it written up in the contract with the producer that this would probably happen."

The cause of the cracking, which first appeared shortly after the memorial opened, is not known for sure, though it might be due to extreme temperature fluctuations in 2005 and 2006, according to the spokesman.

"These things happen with concrete," he added.

Though no firm causes have been named, German media has speculated that the cracks are due to tremors caused by construction projects adjacent to the site, including the new US Embassy, or even vibration caused by commuter trains that pass beneath the memorial.

Costs for repairs have yet to be estimated, but they will be shared by the foundation and Geithner Bau, according to the spokesman. Repairs should begin and be completed this coming winter using injections of synthetic resin.

'A Purely Aesthetic Issue'

The spokesman also added that the memorial will remain open and that there is no danger to visitors. "This is a purely aesthetic issue," he said. "Those slabs will stand for years."

The memorial's concrete slabs reach up to 4.7 meters (15.4 feet) and average over eight tons in weight. They are arranged in a grid pattern in an area of over 13,000 square meters (3.5 acres) in a central location, one block away from the Brandenburg Gate. The monument attracts over 3 million visitors each year.

In an interview with the Süddeutsche Zeitung, designer Eisenman played down design or construction flaws and attributed the cracking to the nature of concrete construction.

"Whenever you build something that is going to sit out in the rain, in the sun and in the frost, sooner or later you're going to have problems, and especially in a climate like Berlin's," he told the newspaper. "Every construction has to be taken care of, repaired and mended. It's completely normal."

Visitors to the memorial on Wednesday generally remained unworried, with some even backing Eisenman's reasoning.

"It's to be expected," said Wilhelm Theisen, 63, a vacationer from Trier. "No concrete is going to last in these extreme conditions. We shouldn't be critical. We should just fix it."

Others even found a silver lining in the development.

"I don't find it that bad, really," said Angela Hiller, 44, from Springer, who came to show the memorial to her 12-year-old son. "It could also serve as a good symbol of the fall of morals and cultures. And it's good that a memorial can have a living function."

Original worries about the memorial's construction focused on the possible effects of weathering, fading and graffiti. A controversy arose in 2003, when it was discovered that Degussa, the company which provided the anti-graffiti chemical coating for the slabs, had connections with the company that produced poison gas for the Nazis.