MINNEAPOLIS (AP) — Authorities said Thursday they have discovered a body in the ruins of a Minneapolis apartment fire, as investigators were honing in on natural gas as a potential cause of the explosion and blaze that left 14 other people injured.

Fire Chief John Fruetel said the investigation was ongoing and the fire’s exact cause was still unknown Thursday — and may never be determined. But, he said, because of the nature of the debris field and because some witnesses spoke of an odor, investigators were focusing on a gas explosion as a possibility.

Becca Virden, a spokeswoman for CenterPoint Energy, said there were no natural gas leaks in the system and the utility received no reports of a suspicious odor before the blast.

Fire officials say they received a call about an explosion about 8:15 a.m. Wednesday, and within minutes a fire raged through the three-story building. In sub-zero temperatures, paramedics responded to find victims on the ground, some with injuries that suggested they may have fallen multiple stories.

Fruetel said that as of Thursday afternoon, authorities had identified 13 of the 14 people injured. Authorities released no identifying information about the person found dead Thursday. The body was turned over to the medical examiner.

Of the injured, three people remained in critical condition at Hennepin County Medical Center, while six were in satisfactory condition, according to the hospital. University of Minnesota Medical Center, Fairview, said it was treating at least two patients Thursday: one was in serious condition with broken bones and one was in good condition with back pain.

Shortly before the body was found Thursday, Fruetel said that two people remained unaccounted for and crews would continue to remove debris from the site in a slow, respectful manner.

The apartment building, which also houses a grocery store, is in the heart of Minneapolis’ Somali community. Several spoke of the heartache of not knowing whether their loved ones made it out of the building alive.

Katra Ali Hethar, of Waite Park in central Minnesota, said her husband was among the missing. Her eyes watered and she was emotional as she spoke about her husband, who moved to Minneapolis because he was looking for work.

“I was talking to him that happy New Year’s night, and that is something I can’t get out of my head,” she said through a translator, as she grasped her head with her hands. “I was told he might have burned in that building.”

Hethar said her husband and his roommate were still missing. She was among several who said they went from hospital to hospital, hoping to find them.

She said police took DNA from her husband’s sons, so they could positively identify any remains that were found.

Shareef Hassan said his friend was also one of the missing.

“I got heartbreak,” Hassan said. “I hope everything is going to be OK.”

Betsy Hodges, who was sworn in as Minneapolis’ new mayor earlier Thursday, said she knows it’s an agonizing time for families.

“The city stands with you,” she said, adding. “When one part of our community is hurting, our entire community is hurting.”

Mohamud Noor, executive director of the Confederation of Somali Community in Minnesota, said his group opened a fund to collect donations for victims and families.