The Vatican's Web site struggled to handle page requests Friday as huge numbers of visitors sought information about Pope John Paul II's ailing health, an Internet performance monitoring firm said.

According to analysis by Netcraft, a U.K.-based Web metrics vendor, the Vatican's Web site has been unavailable to as much as 13 percent of the people trying to access it Friday. Wait times -- how long before the Vatican's home page loads -- also rose precipitously from Thursday, often running as high as 20 seconds.

TechWeb was able to reach the site, but the wait was in excess of 20 seconds.

"With more than one billion Catholics worldwide, the site is likely to struggle while the Pope's condition remains the focus of attention," said Netcraft in a statement.

The 84-year-old Pontiff suffered heart and circulatory collapse Thursday, while early Friday the Vatican released a statement saying this health was "very grave." He was given the sacrament for the sick and dying, more commonly known as the last rites, Thursday evening.

Dynamically-updated graphs of the Vatican site's availability can be found on Netscraft's site.