Investigators looking into last week’s crash of a United Parcel Service Inc. (UPS) B747-400 freighter in Dubai are zooming in on the possibility that a fire started in the cargo hold touching off a chain of events that led to the aircraft to crashing into an uninhabited portion of military compound in the Emirate. The freighter approached the airport too fast and too high to attempt a landing, cruised overhead and short66ly afterward crashed, killing both pilots. The cockpit was reportedly filled with smoke so thick that it obscured the pilots’ view of the instruments. The investigation is being watched closely by a wide range of airlines, pilot groups and safety experts around the world, partly because the wide use of this aircraft type for both cargo and passenger services and because the B747-400 has a good safety record. Despite emerging new signs pointing to a cargo blaze, investigators stressed it was premature to draw definitive conclusions. But the context of the ill-fated flight are known, as about 20 minutes after taking off from Dubai International Airport bound for Cologne, Germany, the cockpit crew declared an emergency, reported smoke in the cockpit and asked to return to Dubai. The pilots reportedly told air-traffic controllers they were struggling with “fire on the deck,” according to people familiar with the transmissions, according to an Associated Press (AP) report. The phrase “deck” commonly refers to the cargo deck. Crash investigators are trying to identify what type of cargo was located near the starboard wing of the three-year-old 747-400 freighter and are trying to determine if lithium batteries were present on the flight, according to the report. Prior to the crash the plane’s automatic diagnostic system sent messages back to UPS headquarters in Louisville, Kentucky warning about a problem in a cargo compartment near the starboard wing, according to the AP report. Investigators were able to recover the voice and data recorders which will greatly aid in the investigation which is being headed by United Arab Emirates’ General Civil Aviation Authority is heading the probe with assistance from Boeing and the US National Transport Safety Board (NTSB).