The night the sky fell over a Scottish town.

Pan American World Airways Flight 103 was a scheduled service from London Heathrow to New York's John F. Kennedy Airport, the transatlantic leg of a journey that had begun in Frankfurt and would end in Detroit.

On the evening of 21 December 1988, six days before Christmas, the Boeing 747 Clipper Maid of the Seas lifted off from Heathrow at 18:25 GMT with 259 people aboard — 243 passengers and 16 crew. Many were travelling home for the holidays: American families, business travellers, and a large group of university students returning from a semester studying in London.

The device

Roughly 340 to 450 grams of Semtex plastic explosive had been concealed inside a Toshiba radio-cassette player, packed into a brown Samsonite suitcase. The unaccompanied bag had been introduced into the airline baggage system and interlined through the airport network before being loaded into a forward cargo container in the hold.

At 19:02 GMT, as the aircraft climbed north over the Scottish borders, the bomb detonated. The forward fuselage and flight deck broke away within seconds. Travelling at hundreds of miles per hour, the aircraft disintegrated across the sky.

Within seconds the aircraft was gone, and burning wreckage was falling on the town below.

On the ground

Debris fell across 845 square miles of southern Scotland and northern England. The largest section — a wing laden with fuel — struck Sherwood Crescent in Lockerbie, gouging a crater more than 150 feet long and destroying twenty-one houses. Eleven residents of the town were killed in their homes. Other large sections came down on Rosebank Crescent and in surrounding fields.

In all, 270 people died: 259 in the air and 11 on the ground. No one aboard survived. It was, and remains, the deadliest terrorist attack ever carried out on British soil.

What followed was the largest and most complex criminal investigation in British history — a search across moors, forests and fields for millions of fragments, and a pursuit of those responsible that would last for decades. That story continues in the timeline and the aftermath.