71 Years ago today: On 11 April 1952 a PanAm Douglas DC-4 crashed into the sea after takeoff from San Juan, killing 52 out of 69 occupants.

Date:Friday 11 April 1952
Time:12:20 AST
Type:Silhouette image of generic DC4 model; specific model in this crash may look slightly different
Douglas DC-4
Operator:Pan American World Airways (Pan Am)
First flight:1945
Total airframe hrs:20835
Engines:Pratt & Whitney R-2000
Crew:Fatalities: 0 / Occupants: 5
Passengers:Fatalities: 52 / Occupants: 64
Total:Fatalities: 52 / Occupants: 69
Aircraft damage:Damaged beyond repair
Location:18 km (11.3 mls) NW off San Juan-Isla Grande Airport (SIG) (   Puerto Rico)
Phase:En route (ENR)
Nature:Domestic Scheduled Passenger
Departure airport:San Juan-Isla Grande Airport (SIG/TJIG), Puerto Rico
Destination airport:New York-Idlewild International Airport, NY (IDL/KIDL), United States of America

The aircraft, named “Clipper Endeavour” took off from San Juan at 12:11 for a flight to New York when the no. 3 engine failed. The prop was feathered at 350 feet and the crew elected to return to San Juan. The aircraft reached an altitude of 550 feet but the no. 4 engine ran roughly and height couldn’t be maintained. To avoid a possible forced landing in a congested area or on coral reef, the aircraft was ditched 11 miles NW of San Juan Airport, 4,5 miles offshore. The rear fuselage broke off behind the bulkhead aft of the main cabin. The plane sank in about 3 minutes.
Probable Cause:

PROBABLE CAUSE: “a) The company’s inadequate maintenance in not changing the No. 3 engine which resulted in its failure immediately subsequent to take-off, and b) The persistent action of the captain in attempting to re-establish a climb, without using all available power, following the critical loss of power to another engine. This resulted in a nose-high attitude, progressive loss of airspeed and the settling of the aircraft at too low an altitude to effect recovery,”