BOSTON -- The following chronology was written using official information from the Hyannis Fire Department and news sources.

Saturday 8:19 a.m. A 911 call is made from the Kennedy compound to the Hyannis Fire Department requesting medical assistance for an emergency. The ambulance is sent to 50 Marchant Avenue in Hyannisport.

8:24 a.m. The ambulance arrives at the Kennedy compound and some treatment is administered at the scene.

8:43 a.m. The ambulance leaves the Kennedy compound with Sen. Kennedy, but no family member accompanies him in the ambulance. (Family members may have followed in a private vehicle.)

8:50 a.m. A request for a Medflight is made from Cape Cod Hospital.

10:10 a.m. Sen. Kennedy is transferred by air at from Barnstable Municipal Airport to Massachusetts General Hospital.

12:27 p.m. Sen. Kennedy's office issues a statement saying, "He is currently under evaluation."

1:55 p.m. Sen. Kennedy's office issues a statement saying, "It appears that Senator Kennedy experienced a seizure."

3:10 p.m. Sources tell NewsCenter 5 that Sen. Kennedy is alert and conscious.

4:53 p.m. A spokeswoman for Sen. Edward Kennedy says he is "conscious, talking, joking with family."

Tuesday 1:00 p.m. Sen. Kennedy's office issues a statement saying the Senator has a malignant brain tumor.

1:20 p.m. Pres. George W. Bush is notified and is "deeply saddened," his spokeswoman says.