The elder son of US vice president Joe Biden is recovering in hospital after suffering a stroke.
Beau Biden, 41, the Delaware attorney general, was transferred to Thomas Jefferson University Hospital in Philadelphia, where he is said to be alert and talking with his family.
The White House said Mr Biden, who is expected to make a full recovery, will undergo further observation and examination.
An ambulance arrived at the university hospital on Tuesday night, escorted by more than a dozen Delaware and Pennsylvania state police and Philadelphia police cars.
Mr Biden returned last year from a year-long deployment to Iraq with his army National Guard unit, where he was a captain and military lawyer in the 261st Theatre Tactical Signal Brigade.
He had considered running this year for the US Senate seat his father held before becoming vice president, but decided instead to run for re-election as attorney general.
More than a decade earlier, in 1972, Joe Biden lost his wife and baby daughter when a tractor-trailer smashed into their estate car when they were getting a Christmas tree.
Beau and his brother Hunter were critically injured, but recovered.
The vice president devoted himself to caring for his two sons as a single father and still will not work on December 18, the date of the accident.
Beau Biden, who is married with two young children, has worked as a lawyer in private practice. He also worked for the Department of Justice between 1995 and 1997 and as an assistant US attorney from 1997 to 2002.