Pan Am Flight 526A ditches near San Juan-Isla Grande Airport in San Juan, Puerto Rico, after experiencing an engine failure, killing 52 people.

Pan Am Flight 526A, a Douglas DC-4, took off from San Juan-Isla Grande Airport, Puerto Rico, at 12:11 PM AST on April 11, 1952 on a flight to Idlewild International Airport, New York City with 64 passengers and five crew members on board. Due to inadequate maintenance, engine no. 3 failed after takeoff, followed shortly by engine no. 4. Nine minutes after takeoff, the aircraft ditched in rough seas 18 kilometres (11 mi) NW of San Juan Airport, broke apart and sank after three minutes. Panicking passengers refused to leave the sinking wreck. 52 passengers were killed, and 17 passengers and crew members were rescued by the United States Coast Guard. After this accident, it was recommended to implement pre-flight safety demonstrations for over-water flights.

Fernando Luis Ribas Dominicci Airport, commonly known as Isla Grande Airport is a small airport in Puerto Rico serving the capital municipality of San Juan and its metropolitan area since 1929. Named after U.S. Air Force Major Fernando Luis Ribas Dominicci, the 102 acres (41 ha) airport is located on San Juan Bay in the Isla Grande district of barrio Santurce in San Juan, about 2 to 6 miles from the Old San Juan historic quarter, Condado and Isla Verde resort areas, Hato Rey business center, and SJU main airport. While its primary activity is general aviation, SIG also handles commercial and private international and domestic flights, particularly between the main island and the Spanish Virgin Islands of Vieques and Culebra. It processed 35,871 total passengers in 2024.

San Juan is the capital city and most populous municipality in the Commonwealth of Puerto Rico, an unincorporated territory of the United States. As of the 2020 census, it is the 57th-most populous city under the jurisdiction of the United States, with a population of 342,259. San Juan was founded by Spanish colonists in 1521, who called it Ciudad de Puerto Rico.