Blood donors have a chance to get free tickets this week to the San Antonio Spurs' season opener. The annual San Antonio Spurs Blood Drive takes place on Thursday from 8:30 a.m. to 1:30 p.m. at the AT&T Center. The first 400 blood donors will get a pair of tickets to the season opener on Wednesday, October 19th. Donors will also receive a Halloween T-shirt. The South Texas Blood and Tissue Center says each donation helps as many as three people. All blood types are needed, but type-O blood is especially in demand.