On Capitol Hill, three Senate office buildings have been sealed off after it was confirmed that a suspicious packaged found in a Senate mailroom contained the toxin ricin. It was also announced publicly for the first time yesterday that ricen had been mailed to the White House in November. The packages sent to the Senate and the White House bore the signature “Fallen Angel.” U.S. Capitol Police said the Senate buildings, which house 5,000 workers, would remain closed for at least four days.