Brazilian officials are still combing through the wreckage of a Learjet 35 that crashed Sunday in São Paulo, killing at least eight people. Witnesses said the airplane, owned by São Paulo-based air-taxi operator Reali Taxi Aerea, was attempting to return to Campo do Marte Airport just after takeoff in light rain, when it slammed nose first into a suburban neighborhood. Killed in the crash were the pilot, copilot and at least six people on the ground, according to São Paulo authorities. The Learjet, registered as PT-OVC, was not carrying any passengers. Meanwhile, last Wednesday the head of Brazil’s embattled National Civilian Aviation Agency, Milton Zuanazzi, resigned amid criticism related to two recent high-profile accidents: the crash in July of a TAM Airbus that skidded off the runway at Congonhas Airport and crashed into a building, killing 199 people; and the September 2006 midair between a Gol Airlines Boeing 737 and an Embraer Legacy 600, which claimed 154 lives.