SAO PAULO >> Forensics experts at Sao Paulo’s morgue had by Tuesday identified the bodies of 35 of the 62 people who were killed in a plane crash in a residential area of Vinhedo last week, killing all aboard, authorities said.

A Brazilian Air Force KC-390 transport plane flew the remains of three passengers back to Cascavel in southern Brazil from where the aircraft had departed, and will continue to transport the bodies as they are released from the morgue.

The morgue said that so far it had released 17 bodies to family members along with death certificates.

The causes that led the French-built ATR-72 turboprop plane operated by regional carrier Voepass to plunge in a flat spin to the ground have yet to be established.

Investigators recovered the plane’s cockpit voice recorder and flight data recorder, and are working on them at Brazil’s aviation accident investigation center (Cenipa) in Brasilia to determine the cause of the accident.

A preliminary report is expected within 30 days with work starting on the plane’s engines that were taken to Cenipa’s facility in Sao Paulo.

Videos of the plane swirling down as it crashed have been analyzed by aviation experts and led some to speculate that ice had built up on the plane. On Friday, Voepass said ice had been forecast at the altitudes at which the plane was flying, but that it should have been within an acceptable level.

The plane was bound for Sao Paulo from Cascavel, in the state of Parana, when it crashed and exploded in the garden of a housing estate in the town of Vinhedo, some 80 km (50 miles) northwest of Sao Paulo. Nobody on the ground was hurt.