The crash of the Jet Rescue Air Ambulance, which operated the Learjet 55, comes two days after the country’s deadliest aviation disaster in almost a quarter century, in Washington, D.C.

A medical transport jet transporting a child who had just completed treatment for a life-threatening condition, her mother and four others crashed into a Philadelphia neighborhood shortly after takeoff Friday evening, exploding in a fireball that engulfed several homes.

Jet Rescue Air Ambulance, which operated the Learjet 55, said in a statement: “We cannot confirm any survivors.” There was no immediate word whether anyone on the ground was killed, but at least six people were treated for injuries at a hospital.