A fourth person has died as gale-force winds from Storm Isha wreak havoc across the UK and Ireland.
A man in his sixties died in a collision on Broad Road in Limavady, Derry/Londonderry on Sunday night, police said.
The van he was driving in collided with a fallen tree and another vehicle at around 9.45pm.
There have also been two fatalities in Ireland and one in Scotland, where a man died after the car he was travelling in also collided with a fallen tree.
The Police Service of Northern Ireland said a second man involved in the collision in Limavady, who was driving a Citroen Berlingo, has been taken to hospital for treatment.
The road was closed as officers carried out enquiries but it has since reopened.
Officers from the Collision Investigation Unit are appealing for witnesses to the collision or anyone who spotted the vehicles on the Broad Road prior to the crash to contact them.
They are especially keen to hear from anyone who captured dash-cam or any other footage. The number to call is 101, quoting reference 1908 21/01/24.
An 84-year-old died in Scotland after the car he was travelling in hit a fallen tree in Grangemouth, Falkirk.
In Ireland, a woman in her 20s died after a van she was a passenger in crashed into a tree at 1.50am this morning.
A man in his 40s died in a car crash in Co Mayo.
Thousands of homes remain without power after Storm Isha battered the UK with gusts of up to 99mph.
Transport services were also disrupted with roads closed, rail lines blocked and flights diverted, while dozens of schools were shut on Monday.
The next storm due to hit the UK and Ireland has been named by the Irish Meteorological Service as Storm Jocelyn, which is expected to cause strong winds from Tuesday night into Wednesday morning.
The UK Met Office issued an amber warning for wind covering western and northern Scotland from 6pm on Tuesday until 8am on Wednesday.
Less serious yellow warnings were issued for wind across much of the UK north of Oxford and Peterborough, and for rain in an area of western Scotland stretching from the border with England to near Inverness.
An 84-year-old man died during Storm Isha after the car he was a front seat passenger in crashed into a fallen tree in Grangemouth, Falkirk, Police Scotland said.
The incident happened on the A905 Beancross Road at around 11.45pm during an amber weather warning issued by the UK’s Met Office which covered the whole country.
Northern Ireland Electricity Networks said 45,000 customers were without power, while Electricity North West also said thousands of properties in north-west England had lost their supply.
Widespread power cuts in the Republic of Ireland were affecting more than 170,000 properties.
Fallen trees affected transport, with Traffic Scotland reporting stretches of the M9 and M74 among the roads closed, while the A1 southbound was blocked at Thorntonloch because of an overturned lorry.
High winds forced the closure of the Tay Road Bridge, M48 Severn Bridge and the A66 in Durham and Cumbria between the A1(M) and the M6, while the Humber Bridge, A19 Tees Flyover and A628 Woodhead Pass in Derbyshire were among stretches closed to high-sided vehicles.
Fallen trees and flooding caused ScotRail to suspend all services from 7pm on Sunday until around 11am when some lines reopened.
A Network Rail spokesman “hundreds of engineers” were deployed with chainsaws and cherry pickers to remove debris from tracks.
He added: “It’s been a wild night, but passengers and railway staff have been kept safe and we will work tirelessly to get the railway back on its feet as quickly as we can.”
Most routes in England and Wales were open on Monday but with some residual delays.
Air traffic control restrictions on Sunday night led to flight cancellations and caused many planes to divert.
Ryanair flights to Dublin from Manchester and Lanzarote in the Canary Islands diverted to the French cities of Paris and Bordeaux respectively.
The Met Office said the highest recorded wind speed during Storm Isha was 99mph at Brizlee Wood in Northumberland, with gusts of 90mph at Capel Curig in Snowdonia on Sunday.
A rare red warning for wind in north-east Scotland was in place until 5am on Monday, with amber warnings covering much of the UK until 6am and further yellow warnings covering the entire country until noon.
A further yellow warning for wind for Scotland, Northern Ireland, north Wales and northern England is active from 4pm on Tuesday until noon on Wednesday.
The Met Office said “everybody” was affected by the storm.
Heavy downpours battered some places, with 28 flood warnings in place in England and 50 in Scotland.
The Police Service of Northern Ireland said the weather put “significant pressure” on the 999 system and urged people to report non-emergencies online or by calling 101.
Chief Superintendent Davy Beck said many roads across Northern Ireland were impassable on Monday morning.
The Met Office said Storm Isha – the ninth named storm to hit the UK since the season began in September – is moving away from the UK on Monday but conditions remained windy with a mixture of sunny spells and scattered showers.
Showers were expected to be heaviest and most frequent in the north and west.