From the Boston Globe:

Doctors believe that Senator Edward M. Kennedy of Massachusetts suffered a seizure at his home in Hyannis Port this morning, then a second seizure as he was being transported by helicopter from Cape Cod Hospital to Massachusetts General Hospital in Boston, according to an official briefed on the situation.

His condition was unclear early this afternoon, as a special police security detail gathered at Mass. General. Kennedy family members were called this morning and told to rush to Boston, according to sources.

The Hyannis Fire Department responded to an emergency call at the storied Kennedy compound at 8:30 this morning, according to the Cape Cod Times. The senator was rushed to Cape Cod Hospital, then flown to Boston. The newspaper published a photograh of Kennedy, strapped to a gurney, being carried to the chopper.

Kennedy, 76, is the senior statesman in one of America's political dynasties. He was first elected in 1962.

Our thoughts and prayers are with the Kennedy family.

Update 1: On CNN, Ed Henry is reporting that a Kennedy source says that the Senator himself at about 10:30 a.m. called someone to say he couldn't host a luncheon. That would have been more than two hours after the originial 911 call.

Update 2: For those who are rightly concerned about the fragile health of a 76-year-old man, this is a timely reminder that John McCain would be 76 at the end of his first term if elected President.