The European Union’s administrative watchdog called Wednesday for a change to Europe’s search and rescue rules following an inquiry into last year’s sinking of a rusty fishing boat, the Adriana, carrying hundreds of migrants while traveling from Libya to Italy.

European Ombudsman Emily O’Reilly said current rules prevent the EU’s border and coast guard agency Frontex from fulfilling its obligations to protect the rights of migrants or act independently of national authorities when boats they use are in distress.

Up to 750 people were believed to be crammed aboard the Adriana when it sank off Greece last June. Just 104 people were rescued — mostly migrants from Syria, Pakistan and Egypt — and 82 bodies were found. Human rights groups accused Greek authorities of failing to properly investigate. Italian authorities were also involved in the incident.

“Why did reports of overcrowding, an apparent lack of life vests, children on board and possible fatalities fail to trigger timely rescue efforts that could have saved hundreds of lives?” O’Reilly asked.