The tunnel was built from 1871 to 1881. Construction was surveyed by the Swiss engineer Louis Favre, who suffered a fatal heart attack inside the tunnel in 1879. Construction was difficult due to financial, technical and geological issues, the latter leading to the death of around 200 workers (the exact number is not known) mainly due to water inrushes; many were also killed by the compressed air-driven trains carrying excavated material out of the tunnel. There were also serious health issues caused by an epidemic of hookworm infection . A strike of the workers in 1875 was crushed by the Swiss Army, killing four and wounding 13.
There is a memorial for the dead workers near the station building at Airolo, created by the artist Vincenzo Vela.