NEW YORK, July 2 (UPI) -- Lawyers for those who worked at the World Trade Center in New York after the 2001 terrorist attacks say 67 percent suffer from respiratory disease.

Papers filed in court Tuesday claim nearly half, 45 percent, have gastrointestinal problems, the New York Post reported. The lawyers, countering claims by the city that 30 percent have not developed serious health problems, say that their information is still incomplete.

"As information continues to be received, there is a clear picture that these plaintiffs' conditions are tending to get worse, not better," the lawyers said in a letter to U.S. District Judge Alvin Hellerstein.

The firefighters and police officers who worked at Ground Zero were among the fittest people in the city before their time there, the letter said.