The cause of the crash has not been determined and investigators said it could take weeks.
"The aircraft just from what we can see, appears to have been taking off to the east It banked to the left, impacted the left wing, contacted the taxi way and slid across that, flipped inverted at some point and came to rest inverted," said Pam Sullivan, NTSB investigator.
The area was sealed off for NTSB and FAA investigators by the Joliet Police Department, which was first to respond after the crash at 9 p.m.
"It looks like the plane was coming in from the west and was going to make a landing and wasn't able to negotiate the landing and crashed upon striking the ground," said Patrick Kerr, Joliet Police Department.
Student pilot Andrew Gallo, who often flies out of Joliet Airport, was nearby when the plane crashed on the runway.
"I saw a big cloud of smoke right behind these fire trucks. I couldn't get too close, but I saw what looked like a Cessna type with the high wings, maybe. It looked pretty bad. There was nothing much left of it," said Andrew Gallo, witness.
The victims' bodies were found inside the burning wreckage. Officials have not determined if the plane was stopping in Joliet to refuel or if there was an emergency.
Seffern was the president of a local flying club and a well known businessman and community leader.
"That was Stu? compassionate, bold, aggressive," said Ron Cox, friend.
The plane, called a 'kit plane,' was built at home by amateurs. It was, however, more than 10 years old but had recently been purchased by the couple.