Emergency personnel move away as a gas fire continues to burn following an explosion at Minnehaha Academy Wednesday, Aug. 2, 2017, in Minneapolis. Several people are unaccounted for after an explosion and partial building collapse Wednesday at a Minneapolis school, fire officials said.  (David Joles/Star Tribune via AP)
Emergency personnel move away as a gas fire continues to burn following an explosion at Minnehaha Academy Wednesday, Aug. 2, 2017, in Minneapolis. Several people are unaccounted for after an explosion and partial building collapse Wednesday at a Minneapolis school, fire officials said. (David Joles/Star Tribune via AP) Credit: David Joles

One school staff member has been found dead and another is still missing following a natural gas explosion Wednesday at a private school in Minneapolis, authorities said.

The body was found in the rubble of a building that partially collapsed during the explosion at the Minnehaha Academy, Minneapolis Fire Chief John Fruetel said during a news conference. The Christian college-prep school serves students from pre-kindergarten through 12th grade.

Both individuals worked at the school, according to the Minneapolis Fire Department. No other details were immediately released.

The school released a statement earlier in the day saying all of its summer program students and staff were โ€œaccounted for and safe.โ€ The school didnโ€™t immediately return a message seeking comment following Fruetelโ€™s news conference.

Contractors were doing work on the building at the time of the blast, which investigators determined was caused by a gas explosion, according to Assistant Fire Chief Bryan Tyner.

Seven adults were hospitalized, including three with critical injuries, at Hennepin County Medical Center. They suffered injuries ranging from head injuries and broken bones to cuts from debris, according to Dr. Jim Miner, the hospitalโ€™s chief of emergency medicine.

Aerial video footage of the schoolโ€™s campus showed part of a building crumbled, windows in other areas blown out and shattered, and bricks and other debris scattered about. Tyner said three people were rescued from the roof of the building shortly after the explosion.

Paul Meskan, who lives across the street from the school, said he was pulling weeds when the blast happened, and he ran over to the school to help pull a man from the rubble. Meskan said he and a few other people found a man who was pinned.

โ€œWe just started digging,โ€ Meskan said. After police and firefighters arrived, โ€œwe kept digging and gas, gas was going. Fire was going. And itโ€™s like, โ€˜weโ€™re not going back until we get this guy out of here.โ€™ And got him out, and they got him on a stretcher.โ€

The Star Tribune reported that city records show Master Mechanical Inc. was issued a permit on June 7 for โ€œgas piping and hooking up meterโ€ at the schoolโ€™s address. Ryan Larsen, a company official, released a statement saying the company was monitoring the situation and referred all questions to the Minneapolis Fire Department.