Pan Am Flight 103 exploded over Lockerbie, Scotland, on December 21, 1988, killing all 259 people on board and 11 people on the ground. The Boeing 747, flying from London's Heathrow Airport to New York's John F. Kennedy International Airport, was destroyed when a bomb was detonated in its forward cargo hold. Bryn Colton/Getty
The plane crashed in Lockerbie 38 minutes after taking off from London. Two Libyans -- Abdel Baset Ali Mohmed al Megrahi and Al Amin Khalifah Fhimah -- were tried for the bombing. Al Megrahi was found guilty in 2001 and sentenced to at least 27 years in prison. Fhimah was found not guilty. Bryn Colton/Getty
American and British investigators found fragments of a circuit board and a timer in the wreckage. Over three years, investigators would question more than 15,000 people and collect thousands of pieces of evidence. Bryn Colton/Getty
Investigators confer at the crash site two days after the tragedy. In July 1990, the British Civil Aviation Authority's Air Investigation Branch officially reported that an explosive device caused the crash. Press Association via AP Images
The body of Kenneth Raymond Garczynski, of North Brunswick, New Jersey, is removed from a plane December 28, 1988, at JFK Airport. Garczynski was the first of the 189 Americans killed in Flight 103 to be returned. Charles Wenzelberg/AP
U.S. President Ronald Reagan pauses at Los Angeles International Airport to comment on the explosion. In 1992, the United Nations Security Council imposed sanctions on Libya over Libya's refusal to hand the suspects over for trial in a Scottish court. Those sanctions were suspended in 1999 when Libya turned the men in. Doug Mills/AP
Al Megrahi is escorted before appearing at the Supreme Court in Tripoli, Libya, for a hearing in February 1992. Nearly 10 years later, in January 2001, he was found guilty in a Scottish court. ManoocherDeghati/AFP/Getty
On the 10th anniversary of the bombing, a woman pays her respects in the Garden of Remembrance at Dryfesdale Cemetery in Lockerbie. Chris Bacon/AFP/Getty
Fhimah, left, walks with Libyan leader Moammar Gadhafi in Tripoli on February 1, 2001, a day after being acquitted. Amr Nabi/AP
The reconstructed remains of Pan Am Flight 103 lie in a warehouse in Farnborough, England, on January 15, 2008. Peter Macdiarmid/Getty
The Rev. John Mosey, right, leaves the Edinburgh High Court in August 2009 as Scottish ministers wrangled over whether to let an ailing al Megrahi return home to die in Libya. Al Megrahi would be released from prison on compassionate grounds due to his terminal prostate cancer. Carl de Souza/AFP/Getty
Al Megrahi gets a hug from Seif al-Islam el-Gadhafi, Moammar Gadhafi's son, after he was released from prison on August 20, 2009. Though he was given just months to live, al Megrahi died nearly three years later, on May 20, 2012. Amr Nabil/AP