A spokesperson from Mayo Clinic Hospital - St. Mary's Campus in Rochester, Minnesota said late Thursday that Gillett is now listed in serious condition, which is an upgrade.

BARRON, Wis. (WEAU) -- The condition of the survivor in a deadly plane crash is reportedly improving.

Thursday afternoon, Barron County Sheriff Chris Fitzgerald said that Hunter Gillett, 18, of Cameron was in critical condition. In a Thursday morning statement, the Barron County Sheriff's Office had listed Gillett in serious condition. Gillett was injured in the Wednesday evening plane crash near Chetek that killed Owen Knutson, 17, of Chetek. Gillett is expected to graduate from Cameron High School on Saturday. He was taken to a hospital in Rochester, MN, where he was receiving treatment at last report.

"A lot of our first responders knew the family," Fitzgerald said. "That's what makes this one...again, the tornado, we knew them, they were our friends...but there's something with kids."

"Usually, I'm not at a loss for words," he said.

Knutson was the pilot of the plane that went into the Red Cedar River, south of Chetek, on Wednesday. Crews pulled the two victims from the river Wednesday evening. They recovered the wreckage Thursday morning, and are keeping it in an airport hangar in Rice Lake.

The National Transportation Safety Board is one of many agencies investigating the cause of the crash.

"We look at two areas, man machine, and environment and this is the machine aspect of it, we'll be looking at the airframe to see if there are any anomalies that could have caused or contributed to this particular accident. We'll look into the pilots background, to see how long he had been flying, what his level of experience was," says Jennifer, Rodi, Senior Air Safety Investigator with NTSB.

"All four corners of the aircraft arrived on scene so it does not look like we have an in flight structural failure of the aircraft," says Rodi.

The sheriff says no Memorial Day or graduation plans are expected to change pending the investigation.

The NTSB should have their full preliminary report filed after the holiday.

BARRON, Wis. (WEAU) -- Investigators have identified the teenagers involved in a deadly plane crash Wednesday evening.

In a statement released Thursday morning, the Barron County Sheriff's Department said Owen Knutson, 17, of Chetek was pronounced dead at the scene of the crash. The statement said that Hunter Gillett, 18, of Cameron is in serious condition in a Rochester, MN hospital. Barron County Sheriff Chris Fitzgerald said that Knutson was a student at Chetek-Weyerhaeuser High School and Gillett is a student at Cameron High School.

Crews responded to the Red Cedar River south of Chetek on several reports of a plane crash around 6:30 p.m. Wednesday. They found the wreckage in the river three miles south of Chetek. Knutson and Gillett were pulled from the water. The sheriff's department said Knutson was the pilot of the two-seater Piper Fixed Wing single engine plane. They had taken off from a private air strip on a property Knutson's family owns south of Chetek. Fitzgerald did not know where the teenagers were headed.

The statement did not elaborate on what else may have led up to the crash or what caused it, and Fitzgerald told WEAU 13 News that he did not know those details. The statement said the sheriff's department along with the Barron County Medical Examiner’s Office, the Federal Aviation Administration and the National Transportation Safety Board are investigating at the scene. It also asked the community to "keep these families and the students of the Chetek and Cameron School districts in your prayers."

BARRON, Wis. (BARRON COUNTY SHERIFF'S DEPARTMENT NEWS RELEASE) -- On Wednesday May 24, 2017 at 6:34pm the Barron County Sheriff’s Department received several calls of a plane crash south of Chetek.

Deputies from the Barron County Sheriff’s Department along with the Chetek Police Department, WI DNR, Chetek Ambulance, Bloomer Ambulance, Chetek Fire Department, Sand Creek Fire Department, WI State Patrol and Life Link Helicopter responded to the scene.

The plane wreckage was located in the Red Cedar River south of Chetek about 3 miles. Two subjects were pulled from the water. Hunter Gillett, 18 of Cameron was taken by Bloomer Ambulance to an Eau Claire Hospital and later flown to Rochester where he is in serious condition. Owen Knutson, 17 of Chetek was pronounced deceased at the scene.

Knutson was the pilot of the 2 seater Piper Fixed Wing single engine plane and took off from a private air strip on the Knutson Property south of Chetek.

The Barron County Sheriff’s Department along with the Barron County Medical Examiner’s Office, the FAA and the NTSB are all on scene handling the investigation.

Please keep these families and the students of the Chetek and Cameron School districts in your prayers.

No media will be allowed on any school district property.

Another tragedy struck Barron County Residents and I have attached the press release. On a weekend we were supposed to... Posted by Barron County Sheriff's Department on Thursday, May 25, 2017