NEW YORK (CBSNewYork) – Security was out in force for this year’s Halloween parade in Greenwich Village. Safety is the top priority heading into major events like the New York City Marathon, Veteran’s Day parade, and the holiday season.

Some of the specific security measures you’ll see are a direct impact of the Halloween terror attack on the west side two years ago.

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Investigators inspect a truck following a deadly act of terror along the West Side Highway in New York on Oct. 31, 2017. (Photo by DON EMMERT/AFP/Getty Images)

CBS2’s Jessica Layton spoke one-on-one with the chief of the NYPD’s Counter Terrorism Unit about the lessons learned from that attack.

“It’s a daunting task and an awesome responsibility that I and everyone else in the P.D. has to protect all the people that come to work here, live here,” Chief James Waters said.

Chief Waters had no way to know he’d spend Halloween night two years ago canvassing the crime scene that had taken over the West Side Highway. He walked up and down that bike path block by block, victim by victim.

“Those images of those victims and the deaths of those victims is still very, very fresh in my mind,” Waters said.

Eight people were killed when Sayfullo Saipov allegedly used a rented truck as a weapon to run down bicyclists and pedestrians. It was a threat that hadn’t wreaked havoc in New York until that day.

Sayfullo Saipov, a 29-year-old Uzbekistan native accused of carrying out a deadly terror attack on Oct. 31, 2017 in New York City. (Credit: NYPD)

The NYPD immediately installed concrete barriers along the path to prevent future truck attacks.

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Since then most of those barriers have been replaced with metal bollards; a security measure now seen at areas across the city.

The bollards are also up in Times Square so cars can’t jump curbs and the protection at this year’s Halloween parade is a direct lesson learned from that tragedy.

“We deploy sand trucks to set up perimeters around certain events so they serve as blocker vehicles,” Waters explained.

“The point is for Halloween, the marathon… we’re always on high alert,” John Miller, Deputy Commissioner of Intelligence & Counterterrorism added.

The recent killing of ISIS leader Abu Bakr Al Baghdadi is also top of mind heading into holiday season events. Authorities know it could mean a renewed call for lone wolf attacks that are unsophisticated, but potentially catastrophic.

“People who are following this propaganda and reacting to these calls. It’s a challenge because if they’re not conspiring with others, not reaching out for resources it’s harder to detect,” Miller said.

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The NYPD says the operating premise in New York is that we are the target – so they’re on guard each and every day, not just at the big events.