Canada was struggling Monday to control wildfires that have forced thousands to flee, crippled oil production and threatened to destroy cities. The province of Alberta has requested federal assistance.

Some 30,000 people have had to flee their homes in the past three days as around 100 fires rage across the province, 29 of them out of control. Federal disaster officials and the military were on standby after Alberta Premier Danielle Smith spoke by phone to Alberta Premier Justin Trudeau to formally request help .

“Canadians stand with Albertans as they deal with these terrible wildfires,” Trudeau said in Ottawa. “We watched footage of the affected communities and I assured Danielle that we will be there to help.”

In Alberta, firefighters have prioritized battling fires threatening homes and businesses. Many roads near the provincial capital, Edmonton, were blocked, while temporary shelters housed evacuees. Oil companies have announced the temporary suspension of their operations, reducing production by more than 125,000 barrels of oil per day.

Many residents and oil workers took refuge in trailers and settled in empty parking lots. Some are staying with friends or relatives.

Dayton Valley, a city of 7,000 people, has been completely abandoned. Trees and surrounding fields were blackened by fire and smoke billowed from a few charred buildings, but most homes appeared intact. It is unclear when residents will be able to return.

In the northern community of Fox Lake, a fire destroyed 20 homes, a store and a police station. Residents were evacuated by boat and helicopter.

Alberta’s premier declared a state of emergency on Saturday and called the wildfire situation unprecedented. The province, one of the biggest oil-producing regions, “is experiencing a hot, dry spring. With so much firewood, a few sparks are all it takes to start some really scary wildfires,” he said.

According to a federal government hazard map, nearly all of Alberta and much of the neighboring province of Saskatchewan, as well as a large swath of the Northwest Territories, face extreme fire risk.

Two out-of-control wildfires in far western British Columbia have also prompted residents to evacuate. Authorities expect strong winds to exacerbate these fires, they warned.

In recent years, Western Canada has been repeatedly hit by extreme weather events, the intensity and frequency of which have increased due to global warming. Today, officials were hoping rain and cooler temperatures would ease the situation somewhat in Alberta, particularly in the south.