It was supposed to be a short, fun flight.

Dan Ortner, a pilot and former Hudson city maintenance worker, and his friend Eric Larson took off from the New Richmond, Wis., airport late Monday afternoon with Larson's adult sons, Michael and Matthew. Ortner had a 7 p.m. meeting, so the flight wouldn't last long.

"They were out for a pleasure ride, just an afternoon flight," said Mike Sime, who knew all the men. "And I don't know what the hell happened."

Ten minutes after takeoff, the single-engine plane crashed in a cornfield in Alden Township, Wis., killing all four men.

About three hours later, shortly after 8 p.m., and several hundred miles southwest, another small plane would crash, killing three more people. Steven Christensen, 59, of rural Pipestone, Minn., and his passengers, Marcos Favela, 18, of Torreon, Mexico, and an unidentified 13-year-old girl from Guadalajara, Mexico, died when Christensen's plane crashed near the town of Holland, in southwestern Minnesota. All were dead at the scene, according to the Sheriff's Office.

Christensen's experimental plane, classified as "amateur built" by the Federal Aviation Administration, was a Wheeler Express model. The four-seater plane was built in 2008 and certified for "airworthiness" in August of that year, according to FAA records.

Steve Hicks, chairman of the Pipestone Municipal Airport Commission, said Tuesday that Christensen, a farmer who grew up in the area, built the airplane on his farm in his spare time and "worked on it for many years," eventually flying it all over the country.

Christensen apparently was related by marriage to his teenage passengers and had been flying them to Minnesota for a family gathering when the plane crashed, Hicks said.

"What a nice guy,'' said Hicks' wife, MaryLou. "It's really a hard loss."

Investigators for the The National Transportation Safety Board (NTSB) and the Federal Aviation Administration (FAA) were at both crash sites Tuesday sifting through debris and gathering evidence to determine what happened.

They are expected to be at the scenes for several more days, but the probable cause of the crashes will likely take more than a year to determine, officials said.

Hudson grieves

While Monday was a particularly tragic day for small plane travel in the region, such crashes are not unusual.

About 1,200 to 1,300 planes, most of them small planes, crash in the United States each year, according to the NTSB.

In 2013, the most recent year where statistics are available, there were 443 aviation fatalities, according to the board's website.

Ortner's plane crashed in a field north of 30th Avenue and east of 150th Street in Alden Township about 5:20 p.m.

The impact of the Beechcraft M35 hitting the ground set the cornfield on fire, according to the Polk County Sheriff's Office. All four bodies were found inside the aircraft.

As news of the tragedy spread through Hudson Tuesday, family and friends quietly gathered to grieve.

Ortner, 44, of North Hudson, had worked for years for the city of Hudson's public works department before moving to the private sector in 2013, City Administrator Devin Willi said.

Ortner had been active in his community, serving on the board of his town's Pepper Fest and even acting as king of the festival in 2007-08.

"He was just a good man," Willi said.

And he loved the sky.

"Dan loved flying and was a great pilot," Mark Ruyak, Ortner's brother-in-law, said in a statement he delivered Tuesday from Ortner's home. "He was a much-loved family member, friend and member of the community. We are heartbroken in grieving for the friends and family of his passengers. We thank you for your prayers and messages and ask that you respect the difficulty of this time for both families."

Like father, like sons

Those who knew the Larsons say the sons were following in their father's footsteps.

Eric Larson, 47, was a lineman for Xcel Energy; Michael, 20, had become an apprentice lineman for the company after studying at Dakota County Technical College. Matthew, 18, recently graduated from Hudson High School and had started classes earlier this month to become a lineman as well, Sime said.

The sons also followed their father by working for Sime at his service station in Hudson.

Eric Larson worked there as a teenager more than 30 years ago.

Michael pulled shifts at the station, too, before graduating from high school and moving to Eau Claire, Wis. He and his fiancée had recently bought a house and were to marry "300 days from today," Sime said.

Matthew Larson also went to work for Sime, and was scheduled to work at the shop Tuesday, Sime said.

"They were great kids. Hard workers. The kind of kids that, when they bought something, they paid for it themselves," Sime said. "What a horrible tragedy."

It was a tragedy that echoed through Hudson's City Hall and fire station Tuesday.

Not only was Ortner a former city employee, but Matthew Larson was part of the Hudson Fire Department's Explorer program. In fact, he was head of the Explorer post, said Fire Chief Scott St. Martin.

Over the last eight or nine years, St. Martin said, four former Explorers have joined the city's part-time fire department.

He said he had hoped that Matthew Larson would join, too.

"He was humble, quiet, a hard worker … but a leader," the chief said. "He was so mature for his age. Matthew was one of the ones we were hoping would continue on."

Now, St. Martin said, plans are in the works to turn Hudson's September Riverfront Fun Run into a benefit for the Explorers.

"Can we make use of this," the chief wondered, "and keep his legacy alive?"

Staff Writer Kevin Giles contributed to this report.

James Walsh • 651-925-5041