Ottawa Mayor Larry O'Brien offered the city's condolences to the family of slain police Const. Eric Czapnik.Ottawa Mayor Larry O'Brien offered the city's condolences to the family of slain police Const. Eric Czapnik. (CBC)The mayor of Ottawa has reacted with shock and sorrow at the stabbing death of one of the city's police officers.

"I join all residents of the city of Ottawa in sorrow over the tragic death of Constable Eric Czapnik," Larry O'Brien said Tuesday evening in a news release. "Our thoughts and prayers go out to his family. We hope this will support them in the difficult days ahead.

"Our community is in shock at this senseless crime. Const. Czapnik's killing gives us pause to reflect on the dangers our first responders face daily on our behalf. The killing of an officer in the service of protecting our public safety is universally condemned, and our city is united in rejecting this violence and supporting our men and women in uniform.

The mayor said he has asked that flags be lowered to half-mast .

A message from the Czapnik family

Today we are faced with the loss of Eric, a police officer, and we grieve the loss of a husband, a father of four children, a brother and a son.

Eric, who worked for three years as an Ottawa police officer, was a proud Polish Canadian who came to Canada in 1990. He was an engaged and dedicated police officer who truly enjoyed working in the community.

He was a proud officer following in the footsteps of his father, who was also an officer for over 30 years in Poland.

This is a most difficult time for our family. We would like to ask the media and the public to respect our privacy during this time.

Thank you.

The Czapnik Family

At The Ottawa Hospital, staff are used to dealing with victims of violence, but Czapnik's killing at the emergency entrance has left them shaken.

"I can't believe something like that would happen, you know what I mean, especially right here at the hospital," said hospital employee Robert Marinoff. "When something like that happens it blows you away, man."

Susan Wilson, another employee, said her co-workers were in a state of disbelief.

"They just can't believe something like that would happen in our city," she said. "You think, 'maybe in Toronto or the United States or something like that,' but we came to work this morning and half the people didn't know what was happening."

A statement issued Tuesday afternoon by Dr. Jack Kitts, the hospital's president and CEO, said in part: "The staff, physicians and volunteers of The Ottawa Hospital wish to extend their sincerest condolences to the wife, children and family of Constable Ireneusz “Eric” Czapnik, to Ottawa police Chief Vern White and to the Ottawa Police Service for the passing of their dear colleague earlier today.

"This morning at 4:30 a.m., Const. Czapnik made the ultimate sacrifice in the service of his city. The Ottawa Hospital is forever grateful for all that officers of our police force and their families do to promote the safety and security of our community."

Kitts said the hospital is co-operating with the police service investigation and won't be answering any questions about the killing from the news media.

The release added that full emergency services at the hospital's civic campus, the site of the killing, are still available.