TL;DR: They didn't actually use them.

The barricades in question –– portable steel structures that can either lay flat or be raised depending on traffic –– seemed to stand out in the memories of several witnesses to the attack.

Both longtime residents and tourists who spoke with CNN and affiliates noted those barriers were not raised while recounting the deadly truck-ramming in the hours that followed.

Indeed, surveillance footage on Bourbon Street showed the pickup truck driving over one such barrier, which was not erect at the time of the incident, and speeding away after, narrowly missing partygoers.

“Those barricades were not up, period,” Jimmy Cothran, a party’s designated driver told CNN’s Pamela Brown. “They had the flimsy orange ones that you could just push over with your finger. We actually thought it was kind of odd.”

Jose Lieras, a tourist from Los Angeles, told CNN affiliate WDSU that the metal barricades at Bourbon and Canal Street were not raised –– instead, he saw “just the standard plastic ones.”

Lieras added that though there were a lot of police stationed at Bourbon Street, cars were still driving by while pedestrians walked all over the street.

In addition to the mechanical barricades, police could also deploy portable wooden and steel barricades and use their vehicles to block roads at certain times.

Michael Guillory, who works at a hotel near the scene of the New Year’s crime, told CNN affiliate WDSU he had “never” seen those steel barricades up in seven years.

On Google Maps Streetview, images of Bourbon Street show that there are also bollard systems on the ground. But the bollards –– vertical posts that can move up and down –– are in the process of being repaired, New Orleans City Councilmember Jean-Paul Morrell said on Wednesday.

The city has been working on installing new, removable stainless-steel bollards along several blocks, from Canal Street to St. Ann Street.

Like the portable and mechanical barricades, the bollards could close the street to traffic when needed to protect pedestrians but be lowered when the street was open to vehicles.

Construction on that project began in November and was expected to carry on through February.

In a city council meeting on Monday, a Department of Public Works official mentioned construction crews had cleared equipment on Bourbon Street ahead of New Year’s celebrations after a councilmember mentioned local businesses being impacted by the construction.

The bollards were the subject of a 2019 report from a private security consulting firm that noted the risk of terrorism in New Orleans’ French Quarter, specifically mass shootings and vehicular attacks, remained “highly possible while moderately probable.”

The report by Interior International, reviewed by CNN, “strongly recommends” bollard mobilization to be fixed and improved “immediately.”

“The current bollard system on Bourbon Street does not appear to work,” said the report.

A source familiar with the assessment told CNN New Orleans owns the types of temporary barriers that could have effectively blocked access to Bourbon Street but didn’t opt to use them on the day of the attack.

The city of New Orleans clearly shares responsibility in those people's deaths and injuries through their ridiculous negligence.