The lower section of the Waterfront Greenway is perhaps the most picturesque loop of New York City's busiest bike path, running along the cool blue waters of the Hudson River between Battery Park and the Little Red Lighthouse by the George Washington Bridge.

The two-lane path — often packed with bikers and pedestrians — became a hotbed of horror on Tuesday when a truck cut onto the path, mowing down people at West Street near the World Trade Center Memorial.

Witnesses described frantic moments with people scrambling for cover as the vehicle plowed down the pathway, part of a scenic, 31-mile slice of asphalt that snakes around the island of Manhattan through parks and under bridges.

At least eight people were killed in an "act of terror," New York Mayor Bill de Blasio said at a press conference Tuesday evening.

Related: 8 killed in 'act of terror' on NYC bike path, suspect in custody

Uber driver Chen Yi said he saw a truck plow into people on the path and heard seven to eight gunshots. Police appeared to be pointing a gun at a man kneeling on the pavement, he said.

“I saw a lot of blood over there. A lot of people on the ground,” Yi said.

Manhattan restaurant chef Eugene Duffy was crossing a street when he heard a commotion, turned back and saw the pickup careening down the path. He says he saw the bodies of two men on the ground, their bikes mangled.

He said he also saw a school bus that appeared to have been T-boned and watched officers at the scene with guns drawn, ducking behind patrol cars.

“So many police came and they didn’t know what was happening,” Duffy said. “People were screaming. Females were screaming at the top of their lungs.”

The neighborhood where the incident occurred is filled with schools and family-centric businesses, such as Manhattan Youth Recreation and Resources Inc., a child care and after-school programs company located on nearby Warren Street. A woman who answered a call at the business on Tuesday afternoon around 4:30 p.m. said she needed to keep the telephone lines free for worried parents.

One Twitter user, Mike Dudas, co-founder of Button, a computer software company based in Manhattan, described the area as “a neighborhood of many kids and families.”

Near the site of the incident are at least six schools: Those schools include: Stuyvesant High School, PS 89, IS 289 Hudson River Middle School, Manhattan Community College, PS 234 Independence School and PS 150 Tribeca Learning Center.

Contributing: Melanie Anzidei, The Bergen Record; The Associated Press