Three people were killed Friday after they were buried alive while working at the Kegati Water Project in Kisii town, police said.
The tragedy which occurred about 4pm on the Kisii-Keroka highway in Maili Mbili caused huge traffic jam on the busy road.
Kisii County police boss Martin Kibet said the tragedy was a landslide.
"Unfortunately, we have lost three men who were connecting the water pipes from Kegati to Kisii town," said Mr Kibet.
Ms Stella Kwamboka, a witness, said whey she screamed when she saw the soil cave.
"It was very horrifying," she said.
One of the victims is said to have left behind a young family of two children and an expectant wife.
Following the tragedy, Kisii Governor James Ongwae toured the site and condoled with the affected families.