Portland, Maine (AP) The owner of an apartment where six people died in a fire has begun serving his jail sentence for a safety code violation.

Fifty-two-year-old Gregory Nisbet reported to Cumberland County Jail Wednesday. He was sentenced to serve a three month sentence for the misdemeanor violation stemming from the fatal Portland blaze.

The Portland Press Herald reports Nisbet’s jail term is believed to be the first for a landlord convicted of a safety code violation. Nisbet was initially indicted on nine counts, including six counts of manslaughter.

The case hinged on the apartment building’s third-floor windows, which were too small to function as secondary means of escape. The building caught fire in the early morning of Nov. 1, 2014. Investigators said it started on a porch in a cigarette butt receptacle.