Provincial health experts say they expect COVID-19 could kill 3,000 to 15,000 people in Ontario over the course of the coronavirus pandemic, the ramifications of which could last up to two years.

Those revelations were part of modelling projections the province released Friday about the spread of COVID-19.

Matthew Anderson, the head of Ontario Health, Adalsteinn Brown, dean of the University of Toronto's public health department, and Dr. Peter Donnelly, who heads Public Health Ontario, held a news conference to explain the models. You can read the full report at the bottom of this story.

"Had we done nothing, Ontario may have suffered 100,000 deaths," Donnelly said, referring to the potential beneficial impact of the province's physical distancing measures. "Thankfully, that is not the position we are in."

WATCH | Dr. Peter Donnelly explains the deadly risk COVID-19 poses

Dr. Peter Donnelly, president and CEO of Public Health Ontario, says the number of fatalities in the province could be reduced to somewhere between 3,000 and 15,000 if strict preventative measures continue to be taken. 1:33

Donnelly said he understands these figures may seem "scary, intimidating" and to many, "unlikely."

But, he said, every year in Ontario, about 1,350 people die from normal, seasonal flu. In a bad year, 1,500 people die.

"When you think that the mortality of this disease is up to 10 times higher, and you remember we have no vaccine, and we have no specific treatment ... then suddenly the figure of 15,000 becomes entirely logical and comprehensible."

Donnelly said Friday that people can change the outcome throughout the province by staying home and physically distancing.

"We need everyone to stay focused in the weeks ahead," he said.

Donnelly also said the time frame of 18 months to two years is in line with other credible models about the pandemic, which account for the possibility of secondary or tertiary waves.

WATCH | Donnelly explains how Ontario can slow the spread of COVID-19:

Dr. Peter Donnelly, president and CEO of Public Health Ontario, describes how the spread of COVID-19 will eventually falter if residents maintain physical distancing measures. 1:37

He did not suggest current restrictions will be in place for that period of time, but later added "we are some way off" from lifting physical distancing policies, especially in densely populated areas like the GTA.

Decisions to ease physical distancing measures will need to be driven by "complicated modelling and science," he said, and done in a "thoughtful" way.

Dr. David Williams, Ontario's chief medical officer of health, said Friday that officials will look to the data to tell them how soon distancing measures could be eased in the future.

"That's not right now, that's not in the next couple weeks or so," Williams said.

"The more everyone does what they're supposed to do now, the shorter the period will be," said Dr. Barbara Yaffe, associate chief medical officer of health for the province.

'Nothing is worth more than a life,' Ford says

Premier Doug Ford and Health Minister Christine Elliott implored Ontarians to do their part to help ease the burden on the province's hospitals, while Ford announced more shutdowns — including some construction projects.

"Everyone has had to pay a price in this war. Daily life has ground to a halt," Ford said.

Given the projections released today, that was the right thing to do, he said.

"Nothing is worth more than a life."

Elliott asked people to remember the personal toll of these deaths.

"These are more than mere numbers," she said. "They are our friends and family and neighbours."

Seniors still the hardest hit, models show

The province's projections note that in Ontario, COVID-19 has a high mortality rate for people over the age of 80, at just under 16 per cent. That's a little under levels seen globally, which are around 20 per cent, Donnelly said.

The mortality rate for people over 70 years old is around 10 per cent, he said.

Background, from left: Matthew Anderson, president and CEO of Ontario Health, Dr. Peter Donnelly, president and CEO of Public Health Ontario and Adalsteinn Brown of the University of Toronto explain their COVID-19 provincial modelling in Toronto. (Frank Gunn/The Canadian Press)

The province's data also comes with some caveats. Its presentation states that models are used to help plan for what "could" happen, and as with any model, the farther out predicted, the more uncertainty there is in those predictions.

There is more confidence in the projections over the next 30 days than over the longer term projections, the province says, adding that "assumptions were used to inform the model."

"Projections and modelling of a brand new viral disease are very inexact," Donnelly said.

Most intensive care units full

The province's modelling also examines the situation in intensive care units.

According to the province, there are currently 410 available ICU beds in Ontario for COVID-19 patients, in addition to the beds that are currently filled with patients. Anderson said that put the province's capacity at 70 per cent.

But, he said, the province is also planning to add 900 additional ICU beds for COVID-19 patients in the coming weeks.

With those additional beds in place, a "best case" scenario would keep the numbers in ICUs from maxing out the available beds, according to the province's projections.

But in a "worst case" scenario, the numbers of people who would need beds could severely exceed what's available. That could happen if people don't practise physical distancing, Anderson said.

"It would push beyond the capacity we can bring," he said.

Moving patients within the province

That ICU capacity is across the province, which means healthcare providers will likely have to move patients and equipment within Ontario depending on need, Anderson said.

According to data obtained by CBC News, the number of available intensive care beds in certain parts of the Greater Toronto Area is rapidly shrinking as the number of COVID-19 patients surges higher.

Just nine critical care beds remain available among the 153 ICU beds in the hospitals of the Central Local Health Integration Network, which includes Mackenzie Richmond Hill, Markham Stouffville, Southlake, Humber River, and North York General hospitals.

Those hospitals are caring for 32 patients with confirmed cases of COVID-19 — double the number they were four days earlier.

The figures come from the April 2 COVID-19 daily report from Critical Care Services Ontario, which was obtained by CBC News but has not been made public by the provincial health ministry. The report does not show a hospital-by-hospital breakdown of ICU bed occupancy rates.

The reports also show just 18 ICU beds available among the 130 critical care beds among the hospitals in the Mississauga Halton Local Health Integration Network — including Trillium Health Partners and the Oakville Trafalgar, Milton District and Georgetown hospitals.

The bulk of COVID-19 patients are cared for in what the province calls Level 3 critical care beds, the highest level of intensive care.

More than 90 per cent of those beds are full In the Central East local health integration network, which includes the Etobicoke General and Brampton Civic hospitals of the William Osler Health System.

The reports also shows high demand for ventilators among those hospitals. There are 33 ICU patients on ventilators, but their total official capacity of ICU beds with ventilators is just 26.

The Ministry of Health has previously said it can provide extra ventilators to hospitals that need them from a centralized provincial stockpile.

Models will change, professor says

Robert Smith, a disease modelling professor at the University of Ottawa, described the model as a useful projection based on available data, though he said the numbers ought to be frequently updated as more research is conducted.

"The best models will be dynamic and they will change as more data comes," he said.

He also warned that Ontario should not become complacent and relax its measures around physical distancing too soon, since the best case scenario is unlikely "unless everything goes just so."

While Ontario is releasing its models, the federal government still hasn't published its own projections for how hard COVID-19 could hit Canada.

"We've been releasing information every single day on the data received from the provinces. We need to make sure the projections we will be releasing will be based on the most accurate information out there," Prime Minister Justin Trudeau said Friday.

"We need to make sure we have a better grasp on the accuracy of the data before we put projections out there."

However, B.C.'s government released projections last week that included details about the pressure the virus could put on ICU beds.

You can read the full Ontario government model below:

On mobile and can't see the model? View it here