KNOXVILLE (AP) — A co-founder of Clayton Homes, a national home-building company, was killed when a helicopter crashed into the Tennessee River, relatives said Tuesday.

Three others escaped the wreckage and were rescued by a pontoon boat that was on the river near Knoxville on Monday night, The Knoxville News Sentinel reported. The survivors refused medical treatment, fire department spokesman D.J. Corcoran said at a news conference late Monday.

Nearby residents called authorities after the crash happened around 7:40 p.m., and the Knoxville Fire Department sent crews into the water to search for the missing victim using underwater sonar devices, according to Corcoran.

Federal Aviation Administration spokeswoman Kathleen Bergen said the victim's body was recovered within a few feet of the crash site around 9:45 p.m.

Jim Clayton, a founder of Maryville, Tennessee-based homebuilder Clayton Homes, and two others survived the crash. Jim Clayton said in a statement that Joe Clayton, who was his brother and business partner, was killed.

"I am devastated and completely heartbroken by the loss of my wonderful brother, Joe," Jim Clayton said. "Joe and I were as close as two brothers can be, and, as only siblings, we have supported each other since growing up together on a farm in West Tennessee and as business partners for decades."

For decades, Clayton Homes has built and sold traditional site-built homes, modular homes, manufactured homes, tiny homes, college dormitories, military barracks and apartments, the company's website said.

Officials didn't immediately say whether the aircraft, a Eurocopter EC-130, was landing or taking off when it went down.

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