"At this point right now, we're shutting down operations for the night," Fruetel said. "The investigative phase will continue tomorrow."

Fruetel said family members of the victim were being notified. But earlier in the day, family members identified the man still missing as 81-year-old John Carlson, a janitor at the school.

Also earlier, Mark Burrington confirmed to KSTP that his fiancée Ruth Berg, 47, a receptionist at the school, had been killed.

The school also confirmed Berg's death in a Facebook post late Wednesday afternoon, saying she had worked at the school the past 17 years.

"As our receptionist, she welcomed everyone with a smile and was always willing to go the extra mile to help our students, families and staff," the post read in part. "She will be greatly missed."

Victims Hospitalized

Nine people were treated at Hennepin County Medical Center, including one who remains in critical condition. HCMC tweeted late Wednesday afternoon that five patients had been discharged. Four remain, including the one in critical condition and three who are listed in satisfactory condition.

At this time we are treating 4 patients; 1 critical, 3 satisfactory from the #MinnehahaAcademy explosion. 5 patients have been discharged. — HCMC (@HennepinMedical) August 2, 2017

"There are people wondering where their loved ones are, and we grieve with them," Minneapolis Mayor Betsy Hodges said at a press conference Wednesday. "We extend our love and our prayers and our thoughts and our hopes. The whole city is with those who still await word of their loved ones."

A spokesperson for HCMC said Bryan Duffey, an assistant boys soccer coach at the school, was the person in critical condition.

Minnehaha Academy head boys soccer coach Steve Barone also confirmed Duffey was among those injured. He had joined the staff last season and was slated to be an assistant with the varsity this fall.

"We spent the entire winter, spring and summer coaching a club team together," Barone said. "We'd gotten really close. We had big plans. So this is a big hit to our soccer family."

Fruetel said the majority of the damage was to the center portion of the building where the explosion occurred, triggering a two-story collapse.

However, he said there is damage all over the building.

Later Wednesday, he said crews were ready to start moving rubble in an effort to find the person at that time still unaccounted for.

KSTP KSTP KSTP/ Chopper 5 Courtesy Mark Burrington KSTP/ Ben Rodgers KSTP/Phil Thiesse KSTP/Chopper 5 Facebook KSTP/Todd Wilson KSTP/Chopper 5 KSTP/ Ryan Raiche Previous Next

Fruetel had said earlier that the situation inside the building was precarious, and rescue workers had to proceed with caution. Among other things, he said they were dealing with debris hanging above areas that needed to be searched.

"It's not going to be quick," he said of the operation. "It's probably going to take us some time."

John Miner, the chief of emergency medicine at HCMC, said most of those being treated Wednesday were adults.

"They were injuries you'd expect from a blast like this," Miner said. "Fractures, lacerations, head injuries. No burns."

Explosion Cause

Hennepin County Emergency Management confirmed in a Facebook post Wednesday afternoon that the explosion was caused "by natural gas from contracted construction being done at the building."

INVESTIGATIVE: Permits Found for Gas Piping and Meter Hookups at Minnehaha Academy

Records reviewed by KSTP show permits were authorized for gas piping and meter hookup at the school on June 7. Master Mechanical, the Eagan-based company that pulled those permits, issued a statement Wednesday afternoon.

"Our thoughts and prayers are with everyone involved in this tragedy and especially with the families and loved ones of those who have died or who have been injured," it read. "We are forever grateful to those first responders and bystanders who came to the aid of all of the injured, including our employees.

"We continue to monitor the situation and are working in full cooperation with the Minneapolis Fire Department. At this time, we are referring all questions about the event to the Minneapolis Fire Department out of respect for their continued efforts."

One of the company's trucks was in the parking lot at the time of the explosion Wednesday.

School Responds

In a statement early Wednesday afternoon, the school said the situation was being managed by Minneapolis emergency personnel, and that all summer program students and stuff were accounted for and safe.

Principal Jason Wenschlag, who had been in Chicago and said he just landed in the Twin Cities, said summer programs usually take place on the lower campus.

Wenschlag was planning to head to the school Wednesday afternoon.

School superintendent Dr. Donna Harris said she was praying for the staff and those affected by the tragedy. She herself was hurt in the explosion and was on crutches Wednesday night.

Classes were scheduled to start at the school on Aug. 23.

A prayer service was held Wednesday night on the school's lower campus.

Sara Jacobson, executive director of institutional advancement for the school, said there were a dozen students in the gym when the explosion happened. She said those students were OK because the gym was not close to the site of the explosion.

Jacobson said there were faculty from the school in the area of the explosion.

Barone said about 14 or 15 of his players were on the soccer field near the building holding captain's practice. But none of those players were hurt.

"Amazingly and thankfully, everybody is OK," he said. "When I saw the helicopter footage, it amazed me that none of the debris reached the soccer field.

In addition to Minneapolis authorities, medics with the St. Paul Fire Department also responded to the scene.

The ATF also confirmed they were on the scene immediately with a K9 and remained on the scene to help with interviews.

Damage to School

Windows were popped out of frames and ceiling tiles fell down inside the school. The damage occurred in the part of the building described by some as the "nerve center of the school."

"That building sustained some heavy damage," Fruetel said. "It's structural integrity is certainly in question right now."

The school was first founded in 1913 and lists an enrollment of 341 in grades 9-12. Though school was not in session in August. The explosion occurred on the school's upper campus, which houses grades 9-12. The south (lower) campus houses grades pre-K through 8.

"If it had been the school year, hundreds of kids would have been in that exact spot," a recent graduate told KSTP. "The lunchroom, the library, the classrooms - everybody walks down that exact stairway.

"If this had been the school year, oh my God, it would have been terrible," he added.

Rescue Efforts

Bryan Tyner, assistant chief of administration for the Minneapolis Fire Department, had earlier said the explosion was believed to be the result of a suspected ruptured gas line, which then caught on fire.

RAW VIDEO: Minneahaha Academy Explosion

Tyner said three people were rescued from the roof.

The state fire marshal's office and the Minnesota Department of Public Safety's Office of Pipeline Safety was at the scene providing support. The Department of Public Safety said it will be left to the discretion of local authorities to ask for additional state aid as the investigation moves forward.

Minneapolis police officers carry out Minnehaha Academy superintendent Dr. Donna Harris following Wednesday's explosion. Minnehaha Academy Upper School explosion A janitor who was inside the building embraces his wife following the explosion at Minnehaha Academy's Upper School Ruth Berg was the confirmed fatality, according to her fiance. Minneapolis Mayor Betsy Hodges talks with neighbors Minnehaha Academy Upper School explosion This man was interviewing for a job when the explosion happened. The back of his shirt was covered with dust. Minnehaha Academy Upper School explosion Minnehaha Academy Upper School explosion Neighbors deliver water following the explosion Minnehaha Academy Upper School explosion Minnehaha Academy Upper School explosion Minnehaha Academy Upper School explosion Minnehaha Academy Upper School explosion Minnehaha Academy Upper School explosion Minnehaha Academy Upper School explosion A Hennepin County Medical Examiner van arrived on the scene Wednesday afternoon Previous Next

Witness Accounts

Ellen Ruiters works at the school and was inside the building at the time of the explosion.

She said she heard "a really loud bang, and some windows popped out and the ceiling tiles came down. We didn't know what happened, so we evacuated the building and when we came out, we saw (what) had happened."

A neighbor who lives near the school said "it was the loudest thing (I) ever heard in my entire life," and that the force of the explosion caused her cupboards to open.

Neighbor to the school: "It was the loudest thing ever heard in my entire life." Blew all her cupboards open. pic.twitter.com/FqbI1ZClcH — Ryan Raiche (@ryanraiche) August 2, 2017

Leaders Respond

Gov. Mark Dayton issued the following statement regarding the explosion:

My office is in continuous contact with the City of Minneapolis and the Minnesota Department of Public Safety, as emergency personnel respond to this emergency. The State will provide any and all resources necessary to aid first responders in their efforts to ensure the safety of all those impacted by this morning's explosion. I thank the many firefighters, paramedics, and law enforcement officers who rushed to the scene this morning, and who are working still to ensure the safety of our children, adults, friends, and neighbors.