A man and his common-law wife died in a fire at their tri-plex in Amherstburg early Sunday morning.

Police said they both died while the man was trying to rescue her from the burning building.

They were both found in the rear unit of the triplex, where the blaze appears to have started. Their names have not been released.

The blaze was called into firefighters after 2 a.m. on Sunday, who rushed to the brick-and-frame home at 216 Richmond St., between Sandwich and Fryer streets.

More than two dozen firefighters were needed to bring the blaze under control.

In a telephone interview on Sunday afternoon, Amherstburg Fire Chief Randy Sinasac told CBC News firefighters from all three department stations were sent to the scene.

Margaret O'Brien is an acting sergeant with Amherstburg Police. She said it took hours to put out the fire on Richmond Street yesterday morning.

"The fire department has had to return for smouldering, and at this time, I could say it was a very difficult fire to extinguish for the fire department. They worked very hard on it. As you can see from the damage, at this time we believe it's severe," O'Brien said.

Occupants inside the other two units escaped the building without injury, Sinasac said.

The cause remains under investigation. Sinasac said the damage is believed to exceed $150,000.