The driver of the state-run transport corporation bus was trying to avoid a pit on the ghat road when the mishap occurred at Mandada, about 10 km from here.
Six people, including two women, were killed on the spot while a 29-year old woman died at a hospital here, police said.
Of the 27 injured, nineteen people had been taken to the government hospital in neighbouring Coimbatore while others were admitted to the government hospital here.
The condition of the bus conductor was stated to be critical, police said.
The bus was proceeding to nearby Coonoor from here.
(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)