(AP) — Work begins Friday to recover the remains of the four people who died when a small plane crashed into a flight training facility at a Kansas airport, authorities said. Jet fuel from the plane burned so hot during the blaze after the crash Thursday morning at Wichita Mid-Continent Airport that portions of the building remained unsafe all day and emergency officials voiced concerns about the stability of the structure. According to witness reports, the plane was "flying low and slow before it entered a left turn," Yeager said. The aircraft was headed to Mena, Arkansas, for painting and interior refurbishing work with Rose Aircraft Services Inc., according to that company's CEO, Keith Rose, who offered his condolences to the victims' families. A tail number shows the plane is registered to Beechcraft Corp.