SAN FRANCISCO >> Lawyers for the operator of an Oakland warehouse charged in a fire that killed three dozen partygoers who were packed into the building aired possible defenses today to a prosecution case that legal experts say appears to be strong.

Derick Almena, 47, was charged with involuntary manslaughter after authorities said he illegally converted a warehouse into housing and an entertainment venue that lacked fire safety systems and was packed with highly flammable material.

Almena’s legal team sought to blame others for the massive Dec. 2 fire and said their client was “deeply distraught” and has struggled with his mental health since the blaze.

In particular, the attorneys said an electrical line was too small to supply the warehouse and that firefighters erred by punching a hole in the roof of the structure shortly after arriving that drew air into the building and fanned the flames. They say firefighters should have instead cut a hole into a wall.

“There could have been more survivors,” attorney Jeffrey Krasnoff said.

Mayor Libby Schaaf said the attorneys were attempting to redirect attention from Almena.

She said Almena and his co-defendant Max Harris repeatedly misled city officials when they insisted they weren’t using the warehouse illegally.

“For years, they worked hard to escape legal scrutiny and deceive city officials,” Schaaf said. “Because of their callous disregard for human life, they deserve to be prosecuted to the full extent of the law.”

Defense attorney Tony Serra said Almena has suffered a near mental breakdown since the fire.

“It has created a sadness … an almost total destruction of his mental stability,” Serra said.

Legal experts say the news conference appears to have been an attempt to influence potential jurors and witnesses.

“They are trying to taint the jury pool by putting down a secondary explanation,” San Francisco Bay Area defense attorney Dan Horowitz said.

He said the attorneys were trying to get their client’s story in front of potential witnesses, who might subconsciously tailor their testimony in Almena’s favor.

Harris, 27, is accused of helping Almena sublease living space and book musical acts at the warehouse.

Both men were arrested Monday and charged with 36 counts each of involuntary manslaughter after a six-month investigation of the Dec. 2 fire that occurred during an unpermitted electronic music concert at the building known as the Ghost Ship.

Stanford University law professor Robert Weisberg said the defendants’ best course could be to seek a plea deal for prison terms considerably less than the 39 years each could face if convicted.

He called the airing of Almena’s remorse and current emotional state “strategically clever but legally irrelevant.” Almena’s state-of-mind before the fire is what matters most, he said.

Almena rented the warehouse as an industrial space in November 2013 and lived there with his wife Micah Allison and their three young children. They were staying at a hotel on the night of the blaze.

Allison spoke publicly for the first time Friday, defending her husband.

“We would never have lived in a place we thought was unsafe,” Allison said. “We were not there the night of the fire on Dec. 2 because it was going to be a loud event, not because we were afraid of the possibility on anything going wrong.”

She said her husband only wanted to provide affordable and safe housing to financially struggling artists in the expensive San Francisco Bay Area.

“We are all grieving,” she said. “My husband is a good man. Max Harris is a good man. They are not greedy. They are not selfish or reckless. I just hope that everyone could have a little bit of compassion for everyone involved.”

Officials have said the cause of the fire might never be known because of all the destruction.

However, Krasnoff said the main PG&E electrical line that supplied power to the warehouse was too small for its needs and could have overloaded, potentially starting the fire.

“We’ve seen no evidence to date that would lead us to believe that our facilities were the cause of the fire,” said PG&E spokeswoman Tamar Sarkissian. She said the utility had no reports of trouble with its equipment at the warehouse and is cooperating with the investigation.

Both men remain jailed on bail of nearly $1.1 million. Jail records don’t list a lawyer for Harris.