At least a further three people were hospitalised, including a passenger from the Maserati.
A tourist who witnessed the aftermath of the crash told KLAS-TV that the burning taxi looked like a fireball.
More people may be hurt, Sergeant Sheahan said.
It is the latest in a series of violent actions on the tourist corridor since the beginning of the year. Two people were critically wounded in a shooting at a parking garage 6th February, and a tourist was stabbed in an elevator at The Hotel at Mandalay Bay ten days later.
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Sergeant Elor Azaria was caught on video shooting dead the wounded assailant, sparking one of the most divisive cases in Israel's history.
CAFOD said: "Hunger is evident in the thinness of children, and the way clothes hang from the bodies of people already suffering."
Police believe it is a "distinct possibility" that Halliwell was a serial killer, beyond the two murders he was convicted for.