A husband and wife in their 70s are dead after an incident at an Ontario hospital that ended in a police shooting late Friday night, the province's police watchdog says.

The Special Investigations Unit (SIU) has taken over the investigation into the man's death, while the Ontario Provincial Police are probing the death of the woman.

SIU spokesperson Jason Gennaro told CBC Toronto that police in Cobourg were initially called to the Northumberland Hills Hospital emergency room for sounds of gunshots at about 11 p.m. ET.

Cobourg is about 115 kilometres east of Toronto.

When police arrived, they encountered a 70-year-old man. Two officers then fired their weapons, Gennaro said.

Linda Davis, president and CEO of Northumberland Hills Hospital, says staff have been trained in how to deal with situations involving weapons but the incident late Friday was 'obviously a stressful situation.' (Christopher Langenzarde/CBC)

The man was struck by bullets and was pronounced dead at the scene.

Officers then found a 76-year-old woman dead. She had suffered a head wound, Gennaro said.

Despite speculation that the woman had been shot, Gennaro would not confirm that, and would not confirm whether the man had a weapon.

"That is something that our investigation is looking to determine," he said.

Meanwhile, all Gennaro would confirm about the couple was that they were both admitted to the hospital "for unknown ailments" and had at one point in the evening been on side-by-side gurneys in a triage area of the ER.

Gennaro would not say how the couple arrived at the hospital, but said they lived within an hour of the facility.

'It's pretty traumatic'

Grace Andrews, 27, was sitting in an adjoining room receiving treatment for a herniated disc when she heard a "huge" bang.

"We thought a table had flipped," she said. "It didn't seem like a gunshot but it was loud."

When her boyfriend Kelly Palmateer went into the hallway to see what had happened, he saw a nurse rushing into the room next door.

"She came out and her face was just blank and she was like, 'somebody call 911,'" he said.

Andrews explained that's when the panic set in.

"You don't expect to have to call 911 when you're in a hospital," Andrews said. "That's what set off the red flag."

Minutes later, they watched police storm in and heard a burst of gunfire, which they mistook for automatic weapons.

The couple barricaded themselves in the room, wondering if they were next.

"There's nothing like being stuck in a room and not knowing what's going on around you and just waiting," Andrews said.

"It's pretty traumatic."

Hospital operations resume

Northumberland Hills Hospital confirmed in a statement that there was a "serious incident" in its emergency department that involved a weapon.

It said its ER had resumed normal operations, the scene was secured, there is no danger to the public, and patients, caregivers and staff members at the hospital are safe.

A Cobourg police vehicles is parked near the main entrance to the emergency room at Northumberland Hills Hospital after the shooting late Friday night. (Peterborough Scanner Feed/Twitter) Care in all other areas of the hospital is continuing as normal, the statement said.

Due to the investigation, ambulances transporting incoming patients to its emergency department were temporarily redirected to other hospitals in the area, but the hospital has resumed full service.

'Obviously a stressful situation,' CEO says

Linda Davis, hospital president and CEO, confirmed the incident occurred inside the hospital's emergency department and its major trauma room was affected.

"We did have to go on ambulance redirect from our emergency department. The rest of our hospital functioned as normal. And we were able to, in fact, work through the event," she said.

Davis said staff and physicians are trained to deal with situations involving weapons and the hospital's employee assistance provider is there to offer support.

She said staff from the provider worked through the night.

Two special constables walk on hospital grounds hours after a shooting inside the emergency department. Two people are dead. (Christopher Langenzarde/CBC) "Our main concern is to, of course, support our staff, physicians that were present," she said.

"It's always difficult. Our staff are trained in critical incidences. They performed very professionally and very well. However, any such event does have an emotional impact.

"It's obviously a stressful situation and it's one that we will continue to revisit with them."

The hospital asked patients already in the emergency department not to move around.

"In the emergency department, we asked the patients to stay within the rooms that they were in, and that was just to make sure the hallways were clear, but they were provided care throughout."

While the SIU would not confirm the man had a weapon, Davis was asked how a patient with a gun could be admitted. She said she could not comment.

She said the hospital plans to review the incident to determine whether anything could have been done differently.

'They're all shook up in there'

Heather Purdy's father is a patient in a second-floor room at the hospital. She said her father heard loud bangs but had no idea what happened.

"Almost shake-the-building bangs," Purdy told reporters outside the hospital on Saturday.

"They're all shook up in there and I can't blame them. It's just shocking for such a small town."

Purdy, who was not in the hospital at the time of the shooting, described the mood inside as one of shock.

"How would you feel if there was a shooting that happened a few feet away from you?"

Further details on the fatal police-involved shooting inside the emergency room in a hospital Cobourg. <a href="https://t.co/yR5l8uu3E3">https://t.co/yR5l8uu3E3</a> —@SIUOntario

The SIU investigates reports involving police where there has been death, serious injury or allegations of sexual assault.

It said six investigators and two forensic investigators have been assigned to investigate the shooting.

Anyone who may have information is urged to contact the SIU's lead investigator at 1-800-787-8529. The SIU is also urging anyone who may have any video evidence related to this incident to upload that video through the SIU website.