A West Chester senior living complex has begun building a new personal-care building that will replace the one in which four residents died during a five-alarm fire in November 2017.

“This is a new era for Barclay Friends, to be sure,” said Sean Kelly, president and CEO of the Kendal Corp., of which Barclay Friends is an affiliate.

The 60-unit building will be constructed from steel and concrete, with an exterior of brick, stone, and flame-retardant siding, Kendal and Barclay Friends executives said Tuesday. Its predecessor, which was reduced to rubble, had exterior walls of wood and vinyl siding, which allowed the fire to quickly climb from the rear patio to the roof on a windy night.

While the construction marks a new beginning for Barclay Friends, questions remain about the tragedy that killed Mildred E. Gadde, 93; Theresa Malloy, 85; and Delores G. Parker, 89, and husband Thomas F. Parker, 92, and temporarily displaced more than 100 others.

The U.S. Bureau of Alcohol, Tobacco, Firearms, and Explosives said in January that it could not determine the fire’s point or origin or why the sprinkler valve was in the off position as the building burned.

Independent fire experts have said the complex’s fire-suppression equipment had a flawed design.

Attorneys for victims’ families say they believe a cigarette ignited the blaze. The Malloy and Parker families have confidentially settled lawsuits against Barclay Friends, said lawyers from the McEldrew Young and Saltz Mongeluzzi law firms.

Barclay Friends’ new personal-care building, which will include 20 units for those with memory impairment, is set to open next spring, complex administrators said.