The National Investigation Agency and other central agencies' officials on Friday visited the Ahmedabad plane crash site, sources said. A London-bound Air India flight -- Boeing 787 Dreamliner aircraft -- with 230 passengers and 12 crew members on board crashed into a medical college complex, moments after taking off from the Sardar Vallabhbhai Patel International Airport in Ahmedabad Thursday afternoon.The central agencies' officials visited the accident site, sources said, without divulging further details.Air India has confirmed that 241 people onboard the flight have died. Only one passenger miraculously survived the crash.The Aircraft Accident Investigation Bureau (AAIB), under the Civil Aviation Ministry, has started a probe into the crash.The AAIB is responsible for the classification of safety occurrences involving aircraft operating in the Indian airspace into accidents and serious incidents.Efforts are on to recover the black box of the Air India flight AI 171 as its analysis will provide vital clues about what triggered the disaster, Gujarat Police and Fire Brigade officials said.A black box is a small device that records information about an aircraft during its flight. Air India Crash: What Is A Black Box And How It Could Help Probe. Read more on Nation by NDTV Profit.