(CNN)Here is a look at what you need to know about the 1983 bombing at a Marine compound in Beirut, Lebanon that killed 241 U.S. service personnel.
October 23, 1983 - 241 U.S. service personnel -- including 220 Marines and 21 other service personnel -- are killed by a truck bomb at a Marine compound in Beirut, Lebanon.
Three hundred service members had been living at the four-story building at the airport in Beirut. There were 1,800 Marines stationed in Beirut at the time.
A multi-national force with units from France, Italy and the United Kingdom was also on peacekeeping duty in Lebanon at the same time.
At the same time the Marine barracks was hit, a suicide bomber drove a pickup truck full of explosives and crashed into a building housing French paratroopers. Approximately 58 French soldiers were killed in the attack.
This was the deadliest attack against U.S. Marines since the battle over Iwo Jima in February 1945.
The bombing was traced to Hezbollah, a militant and political group that originated in Lebanon in 1982. Iranian and Syrian involvement was also suspected.
The Marines were criticized for having lax security at the barracks.
The commander of the barracks, Col. Timothy J. Geraghty, said in congressional hearings investigating the attacks that the compound was hard to defend because it was on flat ground and vehicles drove by it daily to access the airport.
October 23, 1983 - At 6:22 am, a truck carrying 2000 pounds of explosives drives into the Marine compound in Beirut, Lebanon, and crashes into the 1st Battalion, 8th Marine Regimental Battalion Landing Team barracks.
February 1984 - U.S. troops withdraw from Lebanon.
1985 - The Inman Report is released. It finds that Marine officers did not take proper steps to protect the barracks against terrorist attacks.
May 30, 2003 - A U.S. federal judge rules that the terrorist group Hezbollah carried out the attack at the direction of the Iranian government. The ruling allows families of the victims to sue Iran.
September 7, 2007 - U.S. District Judge Royce C. Lamberth orders Iran to pay $2.65 billion to survivors and to family members of the service members killed in the 1983 bombing.
March 1, 2010 - A lawsuit is filed in New York City seeking to force Iran to pay the $2.65 billion awarded to survivors and family members in 2007.
March 30, 2012 - U.S. District Court Judge Royce Lamberth issues a judgment against Iran of $2.1 billion, to be paid to the families and survivors of the attack.
July 2013 - U.S. District Court Judge Katherine Forrest rules to release $1.75 billion of Iranian funds, held in a New York Citibank account, to set up a fund for victims of the 1983 bombing.
July 9, 2014 - A federal appeals court affirms a 2013 ruling that $1.75 billion in Iranian funds should be awarded to the victims' family members.