Early results from a study prompted by the accidents are startling. Among fixed anchors in tropical, marine locales examined for far, 10 to 20 percent would fail with a force of 1 to 5 KN applied. The UIAA standard for fixed anchors is a minimum of 22 KN (1 kN is the weight of a mass of 100 kg).
In addition, while some weakened fixed anchors had visible cracks, others had no cracks and appeared only somewhat corroded. Some of these seemingly less compromised anchors also broke with 1 to 5 KN of force.
Overall, some fixed anchors broke bearing only the weight of a climber. And all examined were stainless steel, which meets the UIAA safety standard and has a reputation of holding up well against corrosion. The corrosion in this particular locale appears to be accelerated by the proximity of the sea and year-round warm, wet weather.
The UIAA Safety Commission, in cooperation with Petzl, launched the study earlier this year. Jean-Franck Charlet, president of the commission, says the UIAA wanted to alert climbers about the danger as soon as possible.
Full article: UIAA