A pump was automatically triggered, discharging pollutant-laden storm water through the secret pipe.

The Peykan was discontinued only last year because of its pathetic mileage and pollutant-laden exhaust.

Nestled in a valley one and a half miles miles above sea level, the Mexican capital suffers most heavily from pollution between November and March, when thermal inversions each morning trap pollutant-laden air and prevent it from rising.