Silverstein's attorney Richard Williamson argued in federal court that damages after the attacks cost WTC owners over $7 billion. One World Trade Center alone cost an estimated $3.9 billion, he said.
"This did not just come out of a hat," Williamson said of the figures. "You can't just say, 'I have economic loss.'"
Roger Podesta, the attorney for the airlines, claimed that the amount sought for by Silverstein for the destruction of the Twin Towers and the construction of the new building would amount to double the compensation owed as he already received $5 billion for the attacks from his insurance company.
Podesta said an $8.5 billion total recovery would amount to more than two and a half times the fair value of the buildings that fell.
WTC owners claim it cost $7 billion to replace the Twin Towers and an extra $1 billion to replace the third building that fell.
U.S. District Judge Alvin K. Hellerstein began listening to both parties' arguments Monday and is expected to rule from the bench when deliberations conclude. The trial is expected to last around three days.
Both the WTC owners and the airlines are claiming that the other is unfairly characterizing their claim. Should Hellerstein conclude that is not the case, Silverstein would have to prove liability in a separate trial.
Michael S. Beach, the airlines' first witness, explained Monday how the loss was calculated.