Police sources said the incident occurred near Nankasagar dam at about 4.30 this morning when the driver of the Uttarakhand Roadways bus going from Haridwar to Tanakpur allegedly dozed off and lost control over the vehicle.
Consequently, the bus fell into a 60 ft deep gorge killing one labourer on the spot and leaving 38 injured, they said.
Police rushed to the spot immediately after being informed and rescued the passengers.
All the injured were admitted in a hospital at Khatima. Later, two of the critically injured were referred to the government hospital at Bareli in Uttar Pradesh.