As tens of thousands of Fort McMurray residents fled the devastating wildfire, at least four were women about to give birth.

One of those women was Susan Harty.

With her home in a cloud of smoke, Harty began to feel painful contractions as she escaped the fire.

She and her fiancé Scott Langenhoff and his two young daughters called 911 as they headed north of the city on Tuesday.

鈥淚 thought for sure Scott was going to have to deliver the baby,鈥 said Harty, whose contractions were becoming more painful as her family fled the flames. 鈥淚 was so panicked.鈥

The couple was told to travel north to a camp in Noralta. From there, Harty was taken by medical convoy to a site in Firebag before being airlifted to Edmonton.

After six hours in labour at Edmonton鈥檚 Misericordia Hospital, Deegan Langenhoff was born.

鈥淒espite circumstances, however hard or tragic they may be, there鈥檚 always some good that comes out of it,鈥 Harty said. 鈥淲e鈥檙e all just happy to be together. I鈥檓 very thankful.鈥

Langenhoff, now the proud father of a healthy baby boy, arrived at the hospital 45 minutes before Deegan鈥檚 birth.

鈥淎s long as everything went well, that鈥檚 all I was worried about,鈥 he said. 鈥淚 wasn鈥檛 worried about making it in time, but I was happy that I did.鈥

The family has yet to find out if their home was destroyed in the fire, but Harty said her family鈥檚 safety is the most important thing.

鈥淲e鈥檙e very fortunate and lucky that all of us got out,鈥 she said.

Staff at the Misericordia hospital say they鈥檝e delivered four babies from Fort McMurray so far.

The Fort McMurray wildfire is now covering an 850-square-kilometre area roughly the size of the City of Calgary.

Most of Fort McMurray鈥檚 80,000 residents fled south after the mandatory evacuation orders were issued on Monday and Tuesday. Others travelled to oilfield camps north of the city.

The Alberta government has also issued a province-wide fire ban.

With a report from CTV Edmonton