Question: Delta Air Lines Flight 1989 was leaving from which Boston airport when it was thought to have been hijacked?
Context: Delta Air Lines Flight 1086 (DL1086/DAL1086) was a scheduled Delta Air Lines domestic passenger flight between Atlanta and New York's LaGuardia Airport.  On March 5, 2015, the McDonnell Douglas MD-88 aircraft veered off the runway shortly after landing at LaGuardia Airport in New York City.  The plane ran up the seawall berm and struck the perimeter fence, sliding along it for approximately 940 ft before coming to rest with the nose of the aircraft hanging over the berm above Flushing Bay.  There were no fatalities, although 24 people suffered minor injuries.  The aircraft was seriously damaged. Delta Air Lines Flight 191 was a regularly scheduled Delta Air Lines domestic service from Fort Lauderdale, Florida, to Los Angeles, via Dallas that crashed on August 2, 1985, at 18:05 ().  The Lockheed L-1011 TriStar operating this flight encountered a microburst while on approach to land on runway 17L (now marked 17C) at Dallas/Fort Worth International Airport (DFW).  The pilots were unable to escape the weather event and the aircraft struck the ground over a mile short of the runway.  The flight hit a car driving north of the airport and two water tanks, disintegrating.  The crash killed 136 people on board, including 128 of the 152 passengers and 8 of the 11 crew, and the driver of the car.  The National Transportation Safety Board (NTSB) determined that the crash resulted from the flight crew's decision to fly through a thunderstorm, the lack of procedures and training to avoid or escape microbursts, and the lack of hazard information on wind shear. Pierre Regional Airport (IATA: PIR, ICAO: KPIR, FAA LID: PIR) is a city owned, public airport three miles east of Pierre, in Hughes County, South Dakota, United States.  The airport was served by two airlines until January 31, 2012 when Delta Air Lines regional affiliate Delta Connection ceased all service.  Great Lakes Airlines now flies both east and west via interline agreements with Delta Air Lines, Frontier Airlines and United Airlines. On September 11, 2001, Delta Air Lines Flight 1989 was a regularly scheduled flight offering nonstop morning service from Logan International Airport in Boston to Los Angeles International Airport on a Boeing 767-300ER aircraft.  This flight was one of several flights considered by the U.S. government as possibly hijacked.  However the flight had not been compromised and soon landed safely in Cleveland, Ohio. Northwest Airlines Flight 253 was an international passenger flight from Amsterdam Airport Schiphol in Haarlemmermeer, Netherlands, to Detroit Metropolitan Wayne County Airport in Romulus, Michigan, United States.  The flight was the target of a failed al-Qaeda bombing attempt on Christmas Day, December 25, 2009, in which a passenger tried to set off plastic explosives sewn to his underwear.  There were 290 people on board the aircraft—an Airbus A330-323E operated by Northwest Airlines, which had merged with Delta Air Lines the year before.  Had the attempt succeeded, it would have surpassed American Airlines Flight 191 as the deadliest aviation occurrence on U.S. soil and tied Iran Air Flight 655 as the eighth-deadliest of all time.  The incident was also the second in 2009 involving an Airbus A330, after the crash of Air France Flight 447 on June 1.  This was also the final accident/incident involving Northwest Airlines as it closed down a month later when it merged with Delta Air Lines. Delta TechOps is the maintenance, repair and overhaul (MRO) division of Delta Air Lines, and is headquartered at Hartsfield-Jackson International Airport (ATL) in Atlanta, Georgia.  With more than 9,600 Technical Operations employees and 51 maintenance stations worldwide, Delta TechOps is a full-service maintenance provider for the more than 750 aircraft that make up the Delta Air Lines fleet.  In addition to maintaining the Delta Air Lines fleet, Delta TechOps also provides MRO solutions and support to more than 150 third-party operators around the world, making it the largest airline MRO provider in North America and the third largest worldwide. This is a list of aviation-related events from 1985.  It remains one of the deadliest years in aviation history for aviation disasters, including the crash of Japan Airlines Flight 123, bombing of Air India Flight 182, crash of Arrow Air Flight 1285, crash of Aeroflot Flight 7425, crash of Iberia Airlines Flight 610, Delta Air Lines Flight 191, Galaxy Airlines Flight 203, and British Airtours Flight 28M, a mid-air collision between Aeroflot Flight 8381 and a Soviet Air Forces transport aircraft, the hijacking of Egyptair Flight 648, and various crashes and other incidents with under 50 fatalities.  August 1985 remains the worst single month for commercial aviation fatalities in history. On March 25, 1969, Luis Antonio Frese hijacked a Delta Air Lines flight 821 (DC-8) from Dallas, Texas to Havana, Cuba.  Frese was indicted in Texas but never returned to the United States to face prosecution.  He reportedly died in Cuba in 1975. Logan International Airport (IATA: BOS, ICAO: KBOS, FAA LID: BOS) , officially known as General Edward Lawrence Logan International Airport, is an international airport located in the East Boston neighborhood of Boston, Massachusetts, United States (and partly in the town of Winthrop, Massachusetts).  It covers 2384 acre , has six runways and four passenger terminals, and employs an estimated 16,000 people.  It is the largest airport in the New England region and 17th-busiest airport in the United States, with 33.5 million total passengers in 2015.  It is named after General Edward Lawrence Logan.  In 2016, Massport reported an 8.5% increase in passenger traffic comparing 2015 to 2016, giving the airport a total of about 36.3 million passengers. DAL Global Services, LLC (DGS), a Delta Air Lines company, is an aviation services provider.  DGS provides services such as aircraft ground handling, aircraft maintenance, cargo handling, and many other aviation-related services.  DGS services over 50 airports within the USA and the Bahamas.  They have contracts with multiple airlines and have not limited themselves to Delta Air Lines.  DGS has over 7,000 employees.  It is headquartered at the Delta Air Lines headquarters in Atlanta.
Answer: Logan International Airport