The investigation into the Air India crash that occurred last month in Ahmedabad, India, killing all 260 people on board, is now focusing on the actions of the plane's captain, according to a report by the Wall Street Journal. The report cites individuals familiar with the preliminary assessment by U.S. officials of evidence retrieved from the crash investigation.

A cockpit voice recording indicates that the captain turned off the switches controlling the fuel flow to the aircraft's engines. The first officer, who was piloting the Boeing 787 Dreamliner, questioned the captain, who was more experienced, about why he had moved the fuel switches to the "cutoff" position shortly after the plane took off. The Wall Street Journal reports that the first officer seemed surprised and then panicked, while the captain appeared to remain calm.

The two pilots involved were Captain Sumeet Sabharwal, who had 15,638 hours of flying experience, and First Officer Clive Kunder, who had 3,403 hours of flying experience.

A preliminary report by India's Aircraft Accident Investigation Bureau (AAIB) released last week, revealed confusion in the cockpit just before the June 12 crash and raised concerns about the position of the engine fuel cutoff switches. The report stated that the fuel switches switched from run to cutoff within a second of each other just after takeoff, but it did not specify how they were switched. The report also mentioned that one pilot was heard on the cockpit voice recorder asking the other why he cut off the fuel, and the other pilot responded that he did not do so.

The preliminary report also indicated that a backup energy source, known as a ram air turbine, deployed almost immediately after the plane lifted off the ground, suggesting a loss of power from the engines. The Wall Street Journal reports that without fuel flowing to the engines, the London-bound plane began to lose thrust and sink.

At the crash site, both fuel switches were found in the run position, with indications that both engines had relit before the crash at a low altitude.

Neither India's Directorate General of Civil Aviation (DGCA), Boeing, nor Air India have responded to requests for comment on the Wall Street Journal report.