Quote: MAYERTHORPE, ALTA. - Four RCMP officers died Thursday when a man with a high-powered rifle began shooting during an investigation into a marijuana grow operation in northwestern Alberta.

"It's my sad duty to inform you that four RCMP officers, four brave young members have been killed in the line of duty," RCMP Assistant Commissioner Bill Sweeney told reporters at a late-afternoon news briefing.

<table align="right" cellpadding="0" cellspacing="4" hspace="4" width="220"> <tbody><tr> <td align="center"> </td> </tr> <tr> <td align="center"> The Quonset hut that police suspect held the marijuana growing operation in Rochfort Bridge, Alta.
</td> </tr> </tbody></table> In Canadian police terms, said Sweeney, "You'd have to go back to 1885, to the Northwest Rebellion, to have a loss of this magnitude. It's devastating."

Police said a fifth person described as "a male suspect" had been found dead at the scene of the crime, a farm near the hamlet of Rochfort Bridge.

The suspect was known to police, said Cpl. Wayne Oakes.

He added that a number of police officers had been guarding the scene since the night before as part of an investigation into illegal marijuana growing and stolen property.

Two of the dead officers had been among the team who were at the Quonset hut overnight, Oakes said.

Rochfort Bridge is located near Mayerthorpe, a town of 1,700 where the RCMP detachment is based, about 130 kilometres northwest of Edmonton.

Three of the dead officers were members of the Mayerthorpe detachment and the fourth was from the RCMP's Whitecourt detachment.

<table align="right" cellpadding="0" cellspacing="4" hspace="4" width="220"> <tbody><tr> <td align="center"> </td> </tr> <tr> <td align="center"> News vehicles were kept away from the scene through the day while police investigated.
</td> </tr> </tbody></table> Family members of the slain officers began arriving at the Mayerthorpe detachment Thursday afternoon, some of them weeping as they were escorted into the building by uniformed Mounties.

Officers stopped responding to radio calls

Earlier in the day, Solicitor General Harvey Cenaiko told CBC News that details of the trouble that broke out at about 10 a.m. Tuesday morning were sketchy.

"As far as we know, there's four officers not responding to their radios, so there is an indication that something is serious here," Cenaiko said.

"[The situation] is still active and they have a number of resources that are on scene or going to the scene."

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</td> </tr> </tbody></table> Sgt. Rick Oncescu, who is with the RCMP in Calgary, said two SWAT teams were called to the area Thursday morning.

A military spokesman said about 20 soldiers and two armoured vehicles were sent to the area after police called for military assistance at about midday.

George Vanderburg, the provincial politician who represents the area, says he and Cenaiko were briefed on the situation around midday Thursday.

He could not provide further details except to say it was a "very serious and very tragic" situation.