Rebuilding officials "have now officially dishonored the memory of the Sept. 11 dead, and they have violated the public trust," said Anthony Gardner of the Coalition of Sept. 11 Families, which last Friday filed a lawsuit to halt the building. The coalition's lawyer, Alan Fuchsberg, said a hearing is scheduled for Wednesday to present their arguments.

Dozens of family members held up renderings provided by rebuilding officials of the memorial next to pictures of their loved ones. Some chanted "no underground memorial."

In an open letter addressed to the U.S. Congress, the group asked that the current underground location of the memorial be removed from the plan. "Besides the safety issues inherent in the underground plan we do not feel that we should have to travel into a cavernous tomb to honor our lost loved ones. The memorial needs to see the light of day and be built with codes that will assure the safety of its occupants," the letter said.

The Coalition of Sept. 11 Families' argument that the memorial would damage the historic footprints has been echoed by preservation groups who have sent letters to rebuilding officials.

The "Reflecting Absence" design, by architect Michael Arad, waschosen two years ago out of more than 5,200 competition entries. It marks the fallen towers near their footprints with two stone reflecting pools at street level, surrounded by trees. The pools go 70 feet below ground, where visitors find surrounding each poolthe names of the nearly 3,000 people killed in the 2001 attacks and the 1993 trade center bombing.

Families have said the memorial would dishonor the dead by placing their names below street level and might be difficult to evacuate quickly.

Stefan Pryor, president of the Lower Manhattan Development Corp., the agency in charge of ground zero rebuilding, said the design would "fulfill the highest standards of both safety and beauty." He said the agency would continue to hear family members' concerns.

Despite the protest, preliminary construction work on the memorial started Monday. Dozens of workers started to clean the memorial site, checking the World Trade Center footprints for damage and installing protective coverings over parts of the original foundation to begin building the memorial. Thomas Bilotti,one of the construction workers at the site, said he was "sad and proud" to be part of the effort.

"It's about time that somebody's working here," said Bilotti. "It's been long enough."