A retired Ontario nurse who was killed in the devastating earthquake that hit Haiti Tuesday evening was on her fourth medical mission to the impoverished nation, her church said Wednesday.

Yvonne Martin, from Elmira, Ont. was among a group of seven nurses who arrived in the Haitian capital Port-au-Prince around 4:30 Tuesday afternoon.

The nurses, who are all from southern Ontario, arrived about 90 minutes before the earthquake hit, Lou Geense, of the Evangelical Missionary Church of Canada, told CTV's Michael Melling.

They were to set up a number of mobile health clinics in poor, rural areas, Geense said.

When the quake hit, the guest house the nurses were staying at collapsed, trapping Martin.

The Waterloo Mennonite Brethren Church posted a brief statement to its website to announce Martin's death and to say the church would be open Wednesday night for those who would like to pray.

"Yvonne passed away as a result of the earthquake in Haiti, where she had just arrived to do medical mission work for the fourth time," the statement read.

"Please continue to pray for her family, especially her husband, Ron. In unity with them, we are consoled to know that she died doing exactly what she loved to do."

Martin retired a couple of years ago after working as a nurse for 36 years at the Elmira Medical Clinic. While retirement led her into humanitarian work, she volunteered at the clinic last fall to assist with its H1N1 flu clinics.

"The need was high, the demand was there and she was there," said Dr. Michael Norris. "She still had a personal commitment to people's health."

Norris said staff and patients at the clinic will miss Martin both for her dedication to her job and her caring nature.

"She was very well integrated into the community and certainly in the office here, so the mood is just very sad and upsetting today," Norris said.

Canadians missing

Meanwhile, former Liberal MP Serge Marcil is missing after also arriving in the Haitian capital Tuesday afternoon.

Marcil, who currently works for Montreal engineering firm SM International, was booked to stay at the Montana Hotel, which reportedly collapsed during the quake.

An official with SM International could not confirm Wednesday afternoon if Marcil had checked into the hotel.

At the same time, Doctors Without Borders said Wednesday it has "grave concerns" for four Canadian staff in Haiti.

"We have not accounted for all our staff," said spokesperson Paul McPhun. "We are very concerned about the welfare and safety of our staff, both international and national."

RCMP officials confirmed earlier Wednesday that two officers who were working in Haiti as part of UN police-training mission -- Supt. Doug Coates and Sgt. Mark Gallagher -- are still unaccounted for.

The other 80 Canadian officers who are part of the mission are safe and sound.

While only 707 Canadians are registered as being in Haiti at the moment, government officials say that number is likely closer to 6,000.

International Child Care Canada, a Markham, Ont.-based NGO, said Wednesday afternoon it had been unable to contact any of its 400 staff members working in Haiti. It's unclear how many are Canadian.

Earlier Wednesday, Foreign Affairs Minister Lawrence Cannon one Canadian had been injured in the 7.0-magnitude quake, while another had sent a text message requesting help -- that person was later found and rescued.

There have been other reports of Canadians surviving the earthquake:

  • Late Wednesday afternoon, The Brethren in Christ Canadian Conference told CTV.ca its 50 volunteers, who arrived last Wednesday to work at the Mission of Hope and Tytoo Gardens orphanages outside Port-au-Prince, are safe and unharmed. A doctor and several nurses who are among the volunteers are now assisting at clinics at the Mission of Hope Hospital.
  • A group of 17 B.C. high school students landed in Haiti just a few hours before the quake. They are all safe, and officials are now looking for a way to transport them back out of the country. The students are accompanied by seven adult chaperones.
  • Fredericton Mayor Brad Woodside was to head to Haiti to help at a village near Port-au-Prince. "They were able to get one call out to Fredericton to let us know that the people in the delegation were all accounted for," Woodside told CTV Atlantic.

With files from The Canadian Press