NEW YORK - For years, the city has been meticulously collecting data about everyone who sets foot into an emergency room.

They collect your basic information, demographics and a set of preliminary diagnostic codes.

It all helps discern patterns that might show a cluster of illness or something unusual going on.

But then the coronavirus pandemic hit, sending the city’s disease tracking infrastructure into disarray. Medical detectives and epidemiologists can't stay on top of it.

“All of our data streams are are stressed right now. So in normal conditions, we are, you know, trying our best to get as much information as we can accurately and report out as much as we can up to date,” said city Department of Health and Mental Hygiene Director of Epidemiology Corinne Thompson.

Every day the number of deaths jumps by the hundreds -- that doesn’t mean hundreds of people are dying in a single night, it’s just the data system struggling to keep up. 

COVID-19 has ravaged the city. Each number represents a life. But as the city tracks the disease and attempts to count the dead, challenges have emerged: the virus is moving fast, community spread is rampant and people are dying faster than the city can count.

"We have a lot of data coming coming in, in the morning. And then we report out twice a day at the moment. We know that there's a lot of disease in the community that we are not reporting," Thompson said.

For now, the city is reporting numbers of people known to have died from the virus because they had a positive test before dying, those who die from COVID-like illness but were never tested are not included in the count.

Then there is the challenge of counting those dying at home. The city has seen a massive spike in those numbers. With funeral homes closed, and a overburdened system, they’re also missing from the count. 

“Overwhelmingly every because of COVID-19, we should count them towards a total as quickly as we can get the full facts. But we understand there's going to be some challenges and some lag in that just because of the sheer nature of the crisis we're going through," said Mayor Bill de Blasio.

“The importance of having this data out there so that it becomes part of the healing process for the city once we get to the other side of this horrible outbreak," said New York City Health Commissioner Dr. Oxiris Barbot.

In recent days, there’s been a stark jump in the number of deaths, every day city and state officials look at different sets of data which usually results in a big difference in the number of reported deaths, just one of the consequences of a system unable to keep up with the pandemic.