The Boeing 747 was 40 minutes into its journey to New York when it was downed by the bombing.
Bodies, fuel and flaming wreckage fell onto the Scottish border town, causing carnage.
An investigation into the attack led to the jailing for 27 years of Abdelbaset Ali Mohmet Al-Megrahi, a former Libyan intelligence officer.
A recent attempt by Megrahi, who is suffering from cancer, to be released from a Scottish prison on ill-health grounds failed.
Libya, formerly an international pariah state, has been welcomed back into the international community in recent years after announcing that it would pay compensation to the families of those killed in the attack.
Lockerbie residents say they still have grim memories of the night the aircraft was bombed.
'Mass of burning'
"It was the nearest thing to hell I ever want to see," George Stobbs, 74, a retired police inspector, said.
"There was this great crater, a great mass of burning," he said of the area where debris from the stricken aeroplane had fallen.
"The heat was intense. I saw an iron gate melting as if someone was putting a blow torch on to butter."
The link to Libya was uncovered after explosive material was traced to a radio-cassette player's circuit board and a Samsonite suitcase.
The bomb had probably been placed on board in Frankfurt, from a non-Pan Am flight which connected with flight 103 at Heathrow, investigators said.
Al-Megrahi and co-accused Al Amin Khalifa Fhimah were eventually tracked down in an international investigation by Scottish police and the US Central Intelligence Agency (CIA).
Al-Megrahi was tried and convicted by Scottish judges at an extraordinary court in the Netherlands, while Fhimah was acquitted.