He was taking the chopper from the city to New Jersey when he crashed at 787 7th Avenue, a 52-story high-rise.
Working for a bank on the building's seventh floor, Kendall Sawyer felt a shake - "jarring enough to notice", but workers weren't sure what it was, she said.
President Donald Trump tweeted about the helicopter crash, praising the NYPD for their swift response and saying that the Trump Administration is there to assist the department in whatever it may need in the investigation.
"Should the helicopter have been flying?"
"It was a little bit insane, a little bit scary" as workers walked down the stairs, she said.
The order to evacuate came minutes later, he recalled.
"I couldn't tell if the smoke preceded the helicopter coming over, or if it was from the helicopter crashing into the building", he said.
It briefly triggered memories of 9/11 and fears of a terrorist attack, but authorities said there is no indication the crash was deliberate. "So as soon as you hear an aircraft hit a building, I think my mind goes where every New Yorker's goes", Cuomo added.
Shortly after dropping off his real estate honcho boss at the East 34th Street heliport, McCormack took off, bound for the chopper's home port in Linden, NJ, officials have said. The visibility at the time of Monday's crash was about two kilometres at nearby Central Park, with low clouds blanketing the skyline. Winds were from the east at 9 miles per hour.
He told CNN authorities need to find out more about the pilot at the time he chose to take off. "He was a veteran helicopter pilot in this area", said Dudley.
McCormack had made at least one emergency landing before.
Firefighters took to the scene as a three-alarm fire broke out.
FDNY Lt. Adrienne Walsh, one of the department's first responders, described the roof scene as "a debris field that was on fire".
McCormack breached the strict 1-mile "no fly zone" that surrounds Trump Tower.
"We are mourning the loss of Tim McCormack", the statement said.
"We are mourning the loss of Tim McCormack, who has flown for us for the past five years", a representative for American Continental, who owned the helicopter, told WPIX.
According to Brazy the pilot, Tim McCormick, 58, took off from the 34th street heliport in Manhattan Monday afternoon after dropping off a passenger. He said a fire after the crash consumed much of the wreckage, and investigators are trying to ID whatever could be salvaged.
His passengers started screaming and crying, the station reported.
McCormack was the Chief for the East Clinton Volunteer Fire Department for over 10 years and also a member of the LaGrange Fire Department.
McCormack graduated from Arlington High School in Lagrangeville. "Tim's technical knowledge and abilities to command an emergency were exceptional", Estes said reading the statement.
The department furthered that McCormack was "extremely respected" by the department and "throughout the Dutchess County fire service".