A family were forced to flee through their bathroom window to escape an arson attack on their home in Staffordshire.
Some flaming material was pushed the letterbox of a semi-detached house in Watling Street, Two Gates, near Tamworth, at about 0400 GMT on Sunday.
Two adults and their teenage children, aged 16 and 18, scrambled on to a flat roof and dropped into the back garden.
No-one was seriously hurt but police said the family were lucky to be alive.
Staffordshire Police said no clear motive had been identified for the attack but it was aware of someone setting fire to a conifer tree in a nearby garden in Parkfield Crescent 20 minutes before the arson attack.
Taxi driver appeal
The family were asleep in their bedrooms upstairs when a smoke alarm in the hallway sounded.
Fire spread through the hallway, up the stairs, along the corridor and into the bathroom, from which they escaped.
The fire was limited to their side of the house and no-one was in the other side of the semi, police said.
Officers have appealed for people in the Watling Street area, close to the traffic lights in Two Gates, to contact them or Crimestoppers if they have any information.
Detectives especially want to speak to a group of three men who stopped and helped the family get out of the house to safety.
"We believe one of the men was a taxi driver who stopped and helped and we would appeal for him to come forward," said investigating officer Det Con Melissa Byrne.
"The family were only alerted to the fire by their smoke alarm and it is extraordinary that no-one was killed or seriously injured," she added.