SAN DIEGO - Finals week was dangerous for Thomas Saenz.

The Navy lieutenant needed armed guards and an armored car to get to an exam site in Kabul, Afghanistan. A deadly bomb attack also caused him to miss his classes - transmitted live via the Internet - but he persevered and earned a master's degree in engineering from the University of Southern California while commanding a top security team.

His class graduated on Friday, as he joins a growing number of service members earning college degrees while deployed in a war zone.

Enrollments for the new GI Bill number more than 480,000, according to the Veteran's Administration, which is starting to track the number of graduates.

It's not known just how many others like Saenz earn their degrees while in combat. A commencement ceremony for 100 war-zone graduates from various universities is planned in late May in Kandahar.

"They really are multi-tasking in the extreme," said Bob Ludwig, spokesman for the University of Maryland University College, adding that the coursework can provide relief from the mental turmoil of war. Completing degrees online is a growing phenomenon, as more traditional public universities join private, for-profit schools in offering courses.

Saenz, a 33-year-old father of two, used the GI Bill to enroll at USC but midway through his studies, the Navy pilot was called to be deployed to Afghanistan.

After getting approval from his professors and Navy commanders, Saenz spent his final year of studies racing to his computer on base at 5 a.m. to attend the live transmission of his classes before dedicating his day to overseeing security for top generals and then-Secretary of Defense Leon Panetta.

He missed a class that required his online presence when a suicide bomber blew himself up near NATO's headquarters in Kabul, killing six civilians.

The base was locked down. Saenz wrote to his professor when the Internet was back up to explain his absence. They understood.