U.S. Sen. Edward Kennedy, 76, remains hospitalized as doctors are trying to find out what caused the seizure.

Saturday morning, Sen. Kennedy suffered a seizure and, after being transported by an ambulance to a local hospital located near his family's Cape Cod vacation house, he was flown to Massachusetts General Hospital where doctors began running test to determine the cause of the seizure.

After some preliminary tests, they eliminated the possibility of a stroke. According to CNN, doctors said the health condition of 76-year-old Democratic icon was serious but he was out of “immediate danger.”

Dr. Larry Ronan, Kennedy's primary care physician said that doctors would have to run some tests in the next days to find out what caused the seizure and to determine a treatment. He also said that Kennedy was” resting comfortably and watching the Red Sox game with his family,” reported CNN.

Kennedy is the youngest brother of late President John F. Kennedy and late Sen. Robert Kennedy. He is now the second-most senior member of the Senate.

This was the second time in the last months when Sen. Kennedy has been hospitalized at Massachusetts General. Doctors operated his neck in October when he had a partially blocked carotid artery. The blockage was discovered in time, while Kennedy was doing his routine back and spine examination check.

Democrats Barack Obama and Hillary Clinton and Republican John McCain whished the Senator well and people all over the country are very concerned about his health.

According to Reuters, White House spokesman Tony Fratto said that President George W. Bush "wishes him a return to good health."