Floodwaters on Wednesday completely cut off Nairobi-Narok road at Mai Mahiu, rendering the section impassable.
The road was de-linked at a section near Karima secondary school causing a traffic snarl-up on either sides.
The waters, as a result of the heavy rains that are pounding most parts of the country, dug a deep gulley on the said section.
The weatherman had predicted that Western, Nyanza, Rift Valley, Northern, Southeastern, Coast, Central and Nairobi will receive a substantial amount of rainfall.
The agency said the rainfall will hit a high of more than 40mm within 24 hours in Nairobi, Western, Central, South and Central Rift Valley.
Destroyed sections of the Narok-Nairobi highway. /COURTESY
Hundreds of travellers were forced to spend the night in the cold after the road was cut off.
Following the incident, police moved in and blocked the road forcing motorists heading to Western Kenya to use the longer Naivasha-Nakuru.
Earlier, the floods swept away five students from the nearby Governors secondary school.
Two were rescued by their colleagues and rushed to Naivasha sub-county hospital. The fate of the rest remains unknown.
Area chief Zachariah Igeria said the floodwaters first swept through the secondary school before the students who were on their way home drowned.
"This is not the first time that this road has been cut off. Engineers must this time have to look for a lasting solution to avoid another calamity in future," he said.