Sen. Edward M. Kennedy, battling a brain tumor, became ill at a post-inauguration luncheon for President Barack Obama on Tuesday and was rushed by ambulance to a hospital. There was no immediate word from medical personnel on the Democrat's condition, although fellow senators said he had suffered an apparent seizure and remained conscious as he was taken for further evaluation. A spokeswoman at the Washington Hospital Center, where Kennedy was taken, said he was awake and answering questions. His wife Vicki and son, Rep. Patrick Kennedy, a Democrat, were with him. Sen. Jay Rockefeller, a Democrat, told reporters that Obama noticed when Kennedy became ill, and rushed over to his table. "There was a call for silence throughout the room," he said. "The president went over immediately. The lights went down, just to reduce the heat, I think."