The craft was about 70 nautical miles off the coast of Malta, within the small island country’s search and rescue zone, according to position data recorded by Alarm Phone, the hotline operator. Within these zones, countries are obligated under international law to coordinate search and rescue operations.

Still, Maltese authorities declined that distress call and at least 32 other communications about the situation, according to interviews with humanitarian groups involved in the rescue and a Reuters review of the groups’ notes, e-mails and recordings documenting the incident.

At one point, a person who answered the phone at Malta’s Rescue Coordination Centre rebuffed a call from a humanitarian worker regarding the boat. “You’re keeping my line busy,” the responder said, and hung up, according to a recording of the call provided to Reuters by Sea-Watch, a German non-profit search-and-rescue group, one of several that notified authorities about the distressed vessel.