The eldest son of the leader of the Conservative party, David Cameron, has died in hospital.
Six-year-old Ivan, who's been described by his dad as "wonderful", was born with cerebral palsy and epilepsy and needed round-the-clock nursing care.
Officials said he became ill overnight and died in hospital on Wednesday.
Cerebral palsy is a condition which effects people's ability to use and move their muscles properly and is normally caused by damage to the brain.
People with the condition find it hard to control parts of the body connected to the damaged areas of their brain.
Mr Cameron and his wife Samantha have two younger children, Nancy and Arthur.