A section of national road 23 in Keuruu, western Central Finland, collapsed at around 9am on Tuesday.
The collapse occurred during construction work in Haapamäki, just west of the Katajamäki overpass, and affected a stretch of the road several metres long.
A construction contractor employee was injured in the collapse, but the injuries were not life-threatening, according to the Centre for Economic Development, Transport and the Environment (ELY Centre) for Central Finland.
After the incident, authorities closed down traffic on Virtaintie. The recommended detour is via roads 346 and 3481.
National traffic centre Finntraffic has advised heavy vehicles to use alternative routes further away, between Virrat and Keuruu.
Road crumbled apart last year
The same section of Virtaintie partially fell apart in October 2024.
Tuesday's collapse started in the southern lane as soil survey drilling work was being carried out, alongside construction work in the northern lane.
The drilling work, which began on Monday, was to check whether the road was at risk of falling apart, according to the local ELY Centre's project manager Jouni Saunamäki.
"We did additional surveys because we were concerned about this situation. In the end, however, this came as a complete surprise," Saunamäki said.
Saunamäki said repairing the road could take several months.
Wet weather damage
Janne Jaatinen, head of the ELY Centre's investment unit, estimated that a single lane could reopen to traffic within two to three days.
According to Jaatinen, the lane that collapsed last year did not give way again because metal reinforcement piles were installed during the repairs. Similar reinforcements are now planned for the section that collapsed on Tuesday morning.
Jaatinen said that recent wet weather may have softened the road, and that vibration from drilling could also have contributed to the collapse.
"A geotechnical expert will examine the collapse area on Thursday. They will be able to better assess the actual cause," he said.
