NEW YORK (CBSNewYork) — It has been one year since our lives changed forever.

On this day last year, the first known COVID-19 case was confirmed in New York City. Fast forward 365 days, the city has seen more than 728,000 cases.

On Monday night, CBS2’s Jessica Layton was at Mount Sinai Hospital, where the first patient was diagnosed.

READ MORECOVID 1-Year: A Look Back On What’s Been Lost And How Tri-State Has Persevered

On March 2, 2020, as we were still learning about the concerning virus at our doorstep, Dr. Angela Chen was just a few hours removed from diagnosing the city’s first positive patient.

“It’s very surreal to think about being there in the moment that kind of set it all off,” Chen said.

COVID VACCINE

Chen was the attending physician in the emergency department of Mount Sinai that Sunday night, when it got word a 39-year-old high-risk patient who’d just traveled to Iran was on her way in.

“I said, ‘You know, I really hope we get this one right, because I think this is it,'” Chen said. “I was petrified that any kind of breach in my PPE meant bringing it home to my family.”

Chen and her husband ended up sending their 1-year-old son to stay with his grandparents in New Jersey, missing first steps and first words.

“We did what we had to to protect him and protect everyone around us,” Chen said.

CORONAVIRUS PANDEMIC

Four days after that first patient in New York, Pam Newman became one of the first infected in New Jersey.

“I think my highest fever was 104 point something,” Newman recalled. “It was just torture.”

The longtime fitness instructor from Teaneck spent an entire month isolated from her husband and three kids.

“It can sneak up and get anybody. You have to be in tune to your body,’ Newman said.

The progress we’ve made has been astounding, but doctors are still working with limited information. It has been a long year, but still just a year of gathering data.

“We don’t understand exactly how virus is transmitted and whose more at risk. We don’t understand who ends up with long-term symptoms,” Chen said. “We’re still in the thick of it despite it being one year later.”

Chen said even after all this time she still gets a pit in her stomach when she has to make a COVID diagnosis, because while many of her patients fare very well and recover quickly, others never get to go home and see their loved ones again.

CBS2’s Jessica Layton contributed to this report

CBSNewYork Team