WARSAW (CNN) -

Eleven people died and one, somehow, survived when a small aircraft belonging to a private parachute school crashed Saturday in Poland, state news reported.

Firefighters learned about the crash near Czestochowa, a city some 140 kilometers (85 miles) north of Krakow, around 4:20 p.m., Polish Press Agency (PAP) reported.

Czestochowa fire Capt. Pawel Liszaj told PAP that arriving firefighters found three people outside the aircraft, one of whom was still alive.

"Unfortunately, everything indicates that he is the only person who survived the crash," Silesian police spokeswoman Joanna Lazar told CNN affiliate TVN.

Authorities later discovered nine bodies inside the plane's wreckage, according to Liszaj.

The survivor -- who was one of the three initially spotted outside the aircraft -- was flown by helicopter to a Czestochowa hospital, Robert Galazkowski, the head of the Polish Medical Air Rescue, told PAP.

The 40-year-old man was conscious from the time he was found, though he suffered many injuries, including to his pelvis, according to the report. He was in serious but stable condition Saturday evening, Galazkowski said.

The cause of the crash wasn't immediately known.