Manhattan's West Side Highway bike path

Tuesday afternoon, a man drove a rental truck down a bike path, plowing down anything and anyone in his way, killing 8 and injuring nearly a dozen more. The attack is the deadliest terrorist incident in NYC since 9/11, just over 16 years ago.

The attack began at 3:05 pm, according to NYPD, when the suspect drove the truck over a curb onto the popular West Side Highway bike path. It ended just blocks away from the World Trade Center, across from the Stuyvesant High School on Lower Manhattan’s west side. Pictures from the crime scene show debris and mangled bicycles littering the path and street.

Six of the victims died instantly; two others died after medics arrived. Others that were injured were taken immediately to nearby hospitals.

“Just out of nowhere I hear–see people, I see people running and screaming and then just multiple gunshots, one after another,” a witness described the scene to CNN reporters.

The terrorist has been identified as one Sayfullo Habibullaevic Saipov, CNN reports. The 29-year-old Uzbekistan native immigrated to the U.S. in 2010, according to the authorities. Saipov drove a pickup truck he rented from the Home Depot down a busy Manhattan bike path for almost a mile.

After crashing into a school bus outside of Stuyvesant High School, Saipov emerged from the vehicle brandishing what appeared to be firearms. Witnesses say they saw Saipov running in the middle of the street holding, what looked like, two guns. It was later reported that the two guns were actually a pellet gun and a paintball gun.

Authorities also reported that Saipov was shouting “Allahu akbar,” Arabic for “God is great,” after leaving the destroyed truck.

An NYPD officer shot Saipov in the stomach. He was taken to Bellevue Hospital for treatment, where he underwent and survived surgery Tuesday evening. Saipov remains in police custody.

NYC Mayor Bill de Blasio called the attack an “act of terror” in a press conference on Tuesday.

“This was an act of terror, and a particularly cowardly act of terror aimed at innocent civilians,” the mayor said of the attack.

According to John Miller, NYPD deputy commissioner for intelligence and counterterrorism, Saipov had been planning the attack for several weeks.

Miller told reporters that a handwritten note had later been found proclaiming the attack was done for ISIS. Found near the truck, the note was written in Arabic. Miller summarized the contents, claiming the “general message of it was that the Islamic State would endure forever.”

At a news conference Wednesday morning, Miller described the note as bearing similar language to instructions written in an edition of Rumiyah, a magazine published by ISIS, from last November. The specific edition calls on ISIS followers to carry out truck attacks. It also instructs them to leave a note pledging their allegiance to ISIS at the scene of the attack.

“He appears to have followed almost to a T the instructions that ISIS has put out,” Miller remarked on the note.

In addition to the note, multiple knives were also found in and around the truck.

The New York Times reports that some of those closest to Saipov have “feared for years that he was heading down the path of extremism.” Counterterrorism investigators continue to drill into the question of whether or not Saipov had any clear and meaningful connections to terrorist organizations. Police reported on Wednesday that it seems likely that Saipov had some connections to other suspects of terrorist investigations.

Miller pointed out that Saipov had never been the subject of any NYPD terrorist investigations, or any F.B.I. investigations. Other law enforcement officials seemed to contradict this, claiming he had been “on the radar” of federal authorities. Saipov apparently first came under the radar for federal officials when he made contact with another Uzbek who was being investigated by terrorist investigators in NY.

New York governor, Andrew Cuomo, told CNN that Saipov was “radicalized domestically.”

“In many ways, this was now a classic case of a radicalization of a domestic jihadist who associated with ISIS, and this is their new playbook,” the governor told CBS in an interview.

Saipov apparently drew concerns from a preacher at a mosque he attended when living in Tampa, FL before moving to New Jersey.

Abdula, the preacher, spoke with The New York Times on the condition that only his first name be used as he feared reprisals from other radicals.

“I used to tell him, ‘Hey, you are too much emotional,’” Abdula told reporters with the NY Times. “‘Read books more. Learn your religion first,’ He did not learn religion properly. That’s the main disease in the Muslim community.”

Abdula appears to have known Saipov rather well. He attended his wedding in 2013 and told reporters that he even worked for Saipov for a time. Saipov once owned a trucking company, Abdula alleges.

Abdula remarked that Saipov had a “character problem,” and was prone to angry outbursts. He recalls that Saipov would get emotional over issues concerning the Muslim community, but relates that he never once heard Saipov speak of committing violence.

Several of the victims were visiting NYC from other countries. One Belgian was confirmed dead and three others injured by Belgium’s minister of foreign affairs. Six of the victims were visiting from Argentina; five were killed, one injured.

Three of those injured in the attack have been released Wednesday. Nine remain hospitalized; despite critical injuries, four are now in stable conditions. Daniel A. Nigro, the commissioner of the city Fire Department, reported that the injuries included two amputations of limbs, and serious head, neck and back trauma.

The stretch of the West Side Highway in lower Manhattan where the attack occurred remains closed off on Wednesday.