PORTLAND (AP) — Scientists with the federal Bureau of Alcohol, Tobacco, Firearms and Explosives are using a computer model to re-create the conditions of an apartment fire that killed six people in Portland in November.

The Portland Press Herald (http://bit.ly/1GLfGd2 ) reported that the computer model could provide answers about how the fire started, why it spread the way it did and why it was so deadly. The fire that ripped through the 94-year-old duplex was the deadliest in Portland in more than half a century.

The paper also reported that the building’s landlord, Gregory Nisbet, is being told to address fire safety issues in another apartment building he owns on a nearby street. City officials inspected the building after getting complaints from tenants about a lack of smoke detectors and other problems.