Officials said they are aware of videos circulating social media that claim to contain 911 recordings made during the attack.

The blame game has started with the Bourbon Street terrorist attack in New Orleans. Why it matters: Officials are seeking answers to how someone could plow a truck through the city's most famous street when millions have been spent to keep it safe.

The driver of the truck who plowed into New Year's Day revelers had pledged support to the so-called Islamic State, the same group the Pulse nightclub shooter had claimed was his inspiration.