Kalymnos: UIAA Confirms Stress Corrosion Cracking After Fatal Climbing Accident
More than six months after a Czech climber died on Kalymnos, the International Climbing and Mountaineering Federation (UIAA) has released its initial findings. Testing confirms stress corrosion cracking and provides new details about the bolts under investigation.
On March 27, 2026, a 60-year-old Czech climber died on the Greek island of Kalymnos after three bolts—permanent anchors installed in the rock to protect climbers—failed on St. Savvas, a route bolted in 2002. The accident raised serious questions about route safety and maintenance at one of the world's premier sport climbing destinations, concerns we examined in our April investigation. On October 16, the UIAA released the first results of its investigation, which began in May. Metallurgical testing of four threaded anchor studs collected near the failed bolts found that they were made of 316L stainless steel, an alloy more resistant to corrosion than the 304 stainless steel initially suspected. The UIAA noted, however, that the studs directly involved in the accident had already been removed and handed over to another team before its investigators arrived.
The teams investigating the accident now agree on the failure mechanism: stress corrosion cracking, which can severely weaken a bolt with little or no visible warning. So far, investigators have found nothing unusual about how the studs were manufactured that would explain the failures. The studs examined, for example, had been threaded using a standard industrial process. Exactly how the cracks developed remains unclear.
Further testing is underway to compare the properties of these older studs with those of newer models. In the meantime, the UIAA is urging climbers to exercise caution at coastal crags and recommends choosing routes that have been rebolted with anchors meeting its standard for resistance to stress corrosion cracking. A full report is expected in the first quarter of 2027.
