The plane is made of composite material and was amateur-built in 2002. It seats four people but only two people from Illinois were aboard, said Schiada.
DeLand Police spokesman Lt. Jack Waples identified the men as Kim Presbrey and Thomas Rhoades.
Three customers were hurt, and two people aboard the plane were hospitalized in Orlando. All of the injuries came from burns, said Luke Schiada, an investigator for the National Transportation Safety Board.
The Volusia County Sheriff's Office said a pilot and a passenger from the plane were airlifted to Orlando Regional Medical Center. Spokesman Gerardo Morales later confirmed to AP that two people had been airlifted there, but he declined to identify them or discuss their injuries.
Emergency dispatch tapes released Tuesday captured the urgency of the situation as customers fled the store a day earlier: A man is heard yelling "Get out! Get out!" on the 911 tape.
Marleny Arevalo, a manager at a nearby Taco Bell fast food restaurant, said she didn't hear or see the crash but Arevalo said she quickly ran with another employee to the shopping center and saw flames in the air shooting from near the back of the Publix supermarket.
"There was a lot of smoke. When I first saw it, there was fire in the air and then it was just a lot of black smoke," she said, adding she tried to go behind the supermarket where fire officials blocked the area. She said they also blocked surrounding roads for hours afterward.
Roth Peeler, who lives about 300 feet (90 meters) behind the store, told the Orlando Sentinel he saw the plane go down.
"A small ... yellow plane spiraled right down and through the roof and just exploded," Peeler said. "Not a piece of the plane came out. It's all in the store."
"I went around the front and saw people running out of the store and trying to get into their cars and out of the parking lot," he added.