
The tiger, who injured a zoo employee last December, was shot as she turned and started towards police who had responded to the emergency.
Read details at San Jose Mercury "Escaped tiger kills visitor, mauls two others at SF Zoo "
I will look for other reports with info and pictures that Mercury might not have, but the SJM is pretty local and seems to have a lot of the information that others don't.
CNN's report "Tiger kills 1, injures 2 at zoo" says that the dead man and the two injured were at a cafe near the tiger pen when attacked. the Mercury report sounded like the killed man was in a different place, but since the three were friends, it would seem likely they were in proximity with each other.
CNN also talked to a doctor that said the two injured were in stable condition and talking, and could be released as early as Wednesday (to start the circuit of talk shows that maul the memories of such incident victims, no doubt).

An AP report at Houston Chronicle "Tiger escapes cage in San Francisco Zoo " has a picture of a keeper feeding Tatiana, who turned out to be the one that escaped though neither CNN nor the AP were able to get the name of the tiger before posting the reports that I've read so far at those sights. (I cannot be certain they will not changed the linked reports later.) The AP report confirms my suspicion that the men were all together when attacked.
None of the reports I read has said, but I assume the two injured men were attacked when they tried to help the first one.
The AP report at Yahoo.com "Tiger kills man at San Francisco Zoo " is a little more recent and identifies Tatiana as the escaped tiger. It has only the same picture as the Houston Chronicle AP report currently, but AP reports at Yahoo often start collecting additional pictures of events.
My lady and I visited the zoo in 1984 on our honeymoon. In August it was great, as it sits near the Western Pacific shore near the motel where we were staying. Lots of cool breezes blew through even in August. I remember the zoo itself having a lot more shade than the Los Angeles one, making it cooler for humans and animals.