PORTLAND, Maine — The landlord convicted of a housing code violation in the case of Maine’s deadliest fire in decades was sentenced on Thursday to serve 90 days in county jail and pay a fine of $1,000.

Gregory Nisbet, 51, was acquitted in October of six manslaughter charges and several other misdemeanors in a trial arising from a fire at his Portland property that killed six young adults in 2014. The sole conviction in the unusual criminal trial was tied to the windows on the third floor of the building at 20-24 Noyes St. being too small to provide a second means of escape.

Cumberland County Superior Court Justice Thomas Warren said that sentencing jail time — which is rare in landlord-tenant cases — was difficult, but that he was moved by the “unimaginable” pain of the the victims’ families.

“This is, hands down, the hardest sentence I’ve ever had to come down on,” said Warren.

After the accidental fire, three people were found dead on the third floor. State prosecutors called the space a “death trap,” and during the trial, a survivor recalled hearing shrieks coming from the top floor before leaping from a window to escape the blaze.

In his first statement during the long court proceedings, Nisbet said that he has been stricken with grief since the night of the fire, but that his sorrow can’t compare to that of the victims’ families.

“There are no winners here. Nothing will wipe the memory of this tragedy from my mind for as long as I live,” he said before the sentencing. “My only hope is that somehow, some way, lives will be saved from the awareness we have all received from this tragic event.”

After the sentence, which was stayed pending a possible appeal, Nisbet declined to comment. He has 21 days to appeal.

The people killed in the fire were David Bragdon Jr., 27; Ashley Thomas, 29; Nicole Finlay, 26, who lived at 20 Noyes St.; and visitors Steven Summers, 29, of Rockland; Maelisha Jackson, 23, of Topsham and Chris Conlee, 25, of Portland.

During the hearing, defense attorney Matthew Nichols called for leniency. Nisbet’s building was merely one of many old Portland homes that were built before the creation of modern building safety codes, Nichols said. He noted the wide media attention to the case and changes in Portland’s housing safety policy as evidence that a jail sentence was not required to deter similar cases.

Two years before the fire, a Portland building inspector responded to a complaint of an illegal dwelling on the third floor of the Noyes Street home, but he never entered the building, according to court testimony.

State prosecutor Bud Ellis and Lisa Leconte-Mazziotti, Finlay’s mother, had asked the judge to give Nisbet the maximum possible jail sentence: six months. Leconte-Mazziotti said the days since her only child’s death have been a “living hell,” and she called for harsh punishment of Nisbet to put other landlords on notice.

“I’ll never understand how a landlord could play tennis while their apartment house was burning and not even know if their tenants made it out OK,” said Leconte-Mazziotti. “Landlords who knowingly allow these conditions to exist are going to kill somebody’s daughter, or son or loved one.”

Warren was not persuaded by the suggestion that Nisbet acted callously in the immediate aftermath of the fire and said that the landlord’s grief and regret seemed sincere.

After the sentence, Ellis said that he believes that 90 days in jail sends a strong message to Maine landlords who have followed the case anxiously. Prosecutors contended during the weeklong trial that Nisbet was criminally responsible for all six deaths and that he should not have allowed residents to live on the third floor. A manslaughter conviction would have set a dramatic new precedent in Maine landlord-tenant law.

Ashley Summers, the widow of Steven Summers, expressed disappointment that Nisbet didn’t get the maximum sentence. Watching her two young daughters grow and flourish since his death has sometimes been painful, Ashley Summers said. She can’t stop thinking of the joy they would have brought their dad.

“I’m doing time my whole life,” she said.