Police watchdog investigating after deaths of 2 men in Burlington, Ont.

The provincial police watchdog says it is investigating after the death of two men at a home in Burlington, Ont., early Tuesday morning.

The Special Investigations Unit (SIU) said in a news release that Halton police responded to a call Tuesday at 12:30 a.m. at a home on Cornerstone Drive.

When police arrived, the SIU says, a 28-year-old man "fled upstairs."

In a press conference Tuesday morning, SIU spokesperson Kristy Denette said early information suggests "there was a struggle between the male upstairs with police."

"There would have been a brief interaction and a conducted energy weapon," she said.

Denette said the 28-year-old had a "self-inflicted injury believed to have been caused by a knife." 

Officers called EMS and provided the man life-saving measures, said the SIU. The man was ultimately pronounced dead at the scene.

The second man, in his 50s, was found dead at the scene, the SIU said. A woman, also in her 50s, was taken to hospital with "non-serious injuries."

Denette said the two men were known to each other.

She said "there's no body-worn camera footage," however, investigators are canvassing and interviewing "a number of witnesses."

The SIU designated two subject officials in the investigation, said Denette, and five officer witnesses will be interviewed for the investigation.

Denette said, "the SIU is mandated to investigate any police involved incident that results in a death, serious injury, et cetera. In this circumstance, there was an attempted arrest made by this individual upstairs and there was an interaction, some conversations and struggle that ensued."

The SIU told CBC News, in an email Tuesday morning, that the Burlington incident did not involve the discharge of a firearm and "it has been classified as a custody death investigation." Halton police are also conducting a criminal investigation.

Police closed Cornerstone Drive due to the investigation, but have since reopened it.