A bomb planted by two members of the PLO exploded soon after takeoff, causing the plane to crash, killing all 47 passengers and crew.

[1][2] On 21 February 1970 HB-ICD[3] a Convair CV-990 Coronado jet named "Baselland" was flying on the route with 38 passengers and nine crew members.

A bomb detonated in the aft cargo compartment of the aircraft about nine minutes after take-off during the ascent on a southerly course at approximately 12:15 UTC in the area of Lucerne north of the St. Gotthard Pass.

The crew tried to turn the plane around and attempt an emergency landing at Zürich but had difficulty seeing the instruments due to smoke in the cockpit.

The aircraft deviated more and more to the west and crashed a short time later in a wooded area at Würenlingen near Zürich, Switzerland, due to loss of electrical power.

[5][6] The Swiss investigating judge, Robert Akeret, personally handed his 165-page report to the federal attorney-general, Hans Walder.

[8] As noted in Kibble (The Arab Israeli Conflict: No Service, Returned & Captured Mail, 2014)[9] - On 21 February 1970 Swissair Flight 330 left Zürich, Switzerland, bound for Tel Aviv, Israel.

A black instructional marking in French was applied to any mail that survived the crash, which translated reads:[9] Correspondence is from "Coronado" that fell at Würenlingen.

At least a dozen international carriers suspended mail and cargo services to Israel following last Saturday's fatal crash of a Swissair jet.

But planes of the West German Lufthansa, the British BEA, and Swissair landed at Lydda Airport today minus their mail bags.

The captain of the Swissair flight refused to take outgoing mail but agreed when informed by postal authorities that he was acting contrary to his company's instructions.

Israel made strong representations to the International Postal Union yesterday against any delays in foreign mail deliveries.In a book titled Schweizer Terrorjahre: Das geheime Abkommen mit der PLO, NZZ journalist Marcel Gyr explored possible reasons, why none of the suspected terrorists were convicted.

In return, Gyr posited, Switzerland granted the then-internationally isolated PLO permission to set up an office at the UN headquarters in Geneva.