NEW ORLEANS — Investigators said Wednesday they suspect multiple people were involved in an attack on New Year's Eve revelers that left 15 people dead and dozens injured along Bourbon Street.

A Texas man driving a rented pickup truck plowed into a crowd near the intersection of Bourbon and Iberville streets in New Orleans' historic French Quarter. The Associated Press, citing a Louisiana State Police bulletin, reported that investigators had reviewed video showing three men and a woman placing an improvised explosive device they believed was tied to the assault.

The pickup truck's driver, Shamsud-Din Jabbar, 42, was shot dead after firing a gun at police, the FBI said. Jabbar, a U.S. citizen from Texas and an Army veteran, also had an Islamic State group flag attached to the vehicle, investigators said. Two officers were wounded but are expected to survive.

"We are aggressively running down all leads to identify any possible associates of the subject," the FBI said in a statement.

The FBI's Houston office said it was searching a home on the north side of the city in connection with the New Orleans attack, but said it couldn't provide additional information. 

In an address to the nation, President Joe Biden stated that the FBI found videos on Jabbar's social media hours before the attack indicating that he was inspired by ISIS and expressed a desire to kill. He also said the FBI was looking into whether an exploding Cybertruck in front of Trump International Hotel in Las Vegas was connected to this attack.

Jabbar appeared to have recorded videos while driving from Texas to Louisiana. The videos are dark so the suspect is not seen but is heard talking about his divorce and about a desire to kill members of his family before ultimately deciding to carry out the attack on Bourbon Street, law enforcement sources told ABC News.

Gov. Jeff Landry issued a state of emergency in Orleans Parish, which Landry said would free up state resources ahead of Super Bowl LIX and Mardi Gras. New Orleans Mayor LaToya Cantrell said a fund was set up to assist victims. She also told people to stay away from secured areas established to investigate the tragedy. 

Landry said that his office intends to be transparent with any defects that may have existed that allowed the suspected attack to happen. 

"We have been working very diligently to address security concerns in preparation for the Super Bowl since October," Landry said. 

Landry said he had intended to make a declaration Thursday to bring together law enforcement at the state, local and federal levels to reinforce security ahead of the Super Bowl and other high-traffic events. 

Earlier Wednesday, New Orleans Police Superintendent Anne Kirkpatrick said that "this man was trying to run over as many people as he could.

“He was hellbent on creating the carnage and damage that he did," Kirkpatrick said. "This was not a DUI situation."

FBI agents said that they found weapons and potential explosive devices in Jabbar's car — concealed in coolers with a remote detonator nearby. Other potential improvised explosive devices were found in the French Quarter. Landry said that the FBI have deemed the area an active crime scene.

ABC News reported that two of the victims were Israeli nationals. A representative of the Israeli Consulate in Houston and the Southwest is “on his way to New Orleans,” at the direction of the Israeli Foreign Minister, a spokesman told ABC.

According to ABC News, the Ford F150 truck used in the attack was a vehicle rented through the Turo app – a carsharing company. Truck owner Rodrigo Diaz told ABC that he rented this truck to an individual through Turo and that he is currently talking to the FBI. He declined further comment.

His wife, Dora Diaz, told ABC News they are devastated.

“My husband rents cars through the Turo app. I can’t tell you anything else. I’m here with my kids, and this is devastating,” she said.

According to the New Orleans government, a set of security barriers set up in 2017 to prevent terrorist attacks along Bourbon Street were in the midst of being replaced when the attack happened. The project started in mid-December and was expected to last until February. 

Cantrell said the barriers were deemed inefficient and the decision was made to make changes to the bollards ahead of the Feb. 9 Super Bowl.

"It gave the city of New Orleans the opportunity to go further and deeper with infrastructure improvements," Cantrell said. "Bollards were not up because they are near completion, with the expectation of being completed before the Super Bowl."

The Sugar Bowl, originally scheduled for Wednesday night in the Caesars Superdome, was postponed to Thursday. The Superdome will be locked down and continuously swept by both bomb squads and agents, Kirkpatrick said.

When asked what made him confident the Sugar Bowl would be safe Thursday, Landry responded simply: "I'm gonna be there."

Rep. Troy Carter, D-New Orleans, said that he is heartbroken by the violence that took place on Bourbon Street.

“My heart is with the victims, their families, and everyone who witnessed this horrific attack during what should have been a joyful New Year’s celebration," Carter said in a statement.

Baton Rouge Police and other law enforcement agencies are sending officers to New Orleans to assist in the investigation and security in the aftermath of the suspected attack, spokespeople said.