SAN ANTONIO -- The third and final phase of a year-long exercise aimed to help local infrastructures test and improve their response to cyberterrorism started Monday.

The University of Texas at San Antonio's Center for Infrastructure Assurance and Security is running the exercise, called "Dark Screen," in partnership with city, county, state and federal agencies, as well as military and local businesses.

Phase Three of "Dark Screen" is a live exercise in which participants will be given cyberattack scenarios that will play out at workplaces.

"The last computer worm and recent power outage on the East Coast are real life examples of problems that can occur with information and power infrastructures," said Jim Jorrie, CIAS exercise director. "By the end of the exercise, we will hope to have developed an exercise model that can then be used in other cities across the nation."

A preliminary report of the "Dark Screen" will be revealed on Sept. 26.

The exercise was first proposed by U.S. Rep. Ciro Rodriguez, D-San Antonio.