A man convicted of killing two young children in a Calgary firebombing has escaped a B.C. prison. He is the second inmate to do so in less than a month.

The Correctional Service of Canada says Michael Douglas Sheets, 48, turned up missing on Sept. 1 following a head count at the Mission Institution, a minimum-security facility in Mission, B.C.

Sheets is serving a 14-year, six-month manslaughter sentence after being hired to firebomb a home in Calgary in Nov. 2004 as part of a love affair revenge plot. The attack left two young siblings, aged four and five, dead, while their mother survived by jumping out a window.

Police say Sheets is five-feet-six-inches tall and weighs 141 pounds. He may be going by the name “John Hala.”

Sheets has a history of escaping custody. In February 2015, he evaded security while on an escorted temporary day pass from the William Head Institution on Vancouver Island. Officers found him a day later.

Mission Mayor Randy Hawes says Correctional Service of Canada promptly notified him of the escape.

“Is this man going to pose a danger to kids, like a sexual predator type guy?” Hawes said. “The answer I got was, ‘No.’”

Sheets is the second inmate to escape Mission Institution in less than a month.

On Aug. 7, John Norman Mackenzie was also found missing following an evening headcount. He is serving a life sentence for second-degree murder and remains on the loose.

Hawes believes that both men are now long gone.

“When these guys walk away, they generally want to put as much distance as they can between here and wherever it is they're going,” he said.

Living directly across the street from the Mission Institution’s low chain-link fence, Art Camozzi wonders what the prison is going to do to enhance security.

“We've only been here five months and there's three guys that have escaped since we've been here,” Camozzi told CTV Vancouver. “It's kind of concerning that people with a criminal background are allowed to walk around free.”

Correctional Service of Canada declined a request for an interview Monday, saying that staff are busy focusing their attention on capturing the escapees.

With files from CTV Vancouver