Two women and an 11-year-old boy narrowly escaped injury when a tree fell on two cars near Nixon's Corner outside Londonderry on Thursday.
The Fire and Rescue Service said the tree hit the bonnet of one car and caused minor damage to a second vehicle.
The three people were treated for shock at the scene.
Many roads were affected by flooding and fallen trees as gale-force winds created treacherous driving conditions across Northern Ireland.
6,000 homes, mainly in Omagh and Dungannon, were also without electricity.
The A6 Glenshane Road at Cross and the A40 Letterkenny Road are still flooded, and drivers are asked to take particular care.
The B72 Liskey Road between Victoria Bridge and Strabane is closed, as is the B48 Duncastle Road between Donemana and Newbuildings.
Colin Brown from Roads Service said it was a "particularly busy night" for their crews, and said they were continuing to work to keep the roads open.