The Lockerbie bombing is being marked at home and abroad by politicians and officials 25 years after the terrorist atrocity.
The British Government is sending Scotland Office minister David Mundell to a memorial ceremony on Saturday in the US, from where 189 of the 270 victims came.
“I am pleased to represent the UK Government at the memorial service in Arlington National Cemetery,” said Mr Mundell, whose constituency includes Lockerbie. “The service will provide time to pause for thought and remember the loss of life on that tragic night.”
A cairn of red sandstone – one brick for every life lost – stands at the cemetery in Virginia. The blocks come from Corsehill Quarry, near Annan, Dumfriesshire.
First Minister Alex Salmond will attend a ceremony at Dryfesdale Cemetery, Lockerbie.
Lord Wallace, Advocate General for Scotland and former Scottish Liberal Democrat leader, will also attend.
A service will be held at Westminster Abbey at the same time as the commemorations in the US. It will be attended by Scottish Secretary Alistair Carmichael and Deputy First Minister Nicola Sturgeon.
Pan Am flight 103 exploded above Lockerbie on the evening of December 21, 1988, killing everyone on board the Boeing 747 and 11 people on the ground. There were 43 people from the UK – in Lockerbie and on the plane – among the dead.
Two Libyan suspects were eventually sent to trial at a special Scottish court in the Netherlands.
Only Abdelbaset al Megrahi was convicted of the bombing. He was found guilty in January 2001 and given a life sentence.
Megrahi was diagnosed with prostate cancer in 2008, leading to a decision to free him under compassionate release rules.
Scottish Justice Secretary Kenny MacAskill took that decision on August 20, 2009, sparking a huge row among politicians on both sides of the Atlantic.
Megrahi died in the Libyan capital Tripoli in May last year.
A petition by pressure group Justice For Megrahi has been inching through the Scottish Parliament with calls on the government to open an inquiry into the conviction.