The school was oddly quiet when Diego finally left his living quarters. Usually there was a bustle in the hallway of early students and teachers and guards milling about, but only a few people moved about. This struck him as odd until his eyes caught sight of Sam moving toward him.
“Hey something’s happened down the shore,” Sam said excitedly as the two drew near, " Looks like somethings blown up a few miles away. You should go get that super strong spyglass of yours and come up into the tower." Sam spun on his heals and hurried off
Diego can continue to his classroom, it is still early and class is at least an hour away, or he can go back to his room and get his portable telescope. Diego even seems like the kind of guy who has some interest in astronomy so lets say he has a pretty good salvaged tripod telescope which could be taken as well and go to the tower.
Tower is the old air control tower of the San Francisco National Airport but almost a mile away as you have to go around a body of water. Diego is at the Community college just north of Seaplane Harbor if you look at a map of San Francisco Airport
Diego retrieves his collapsible telescope and retrieves his bike. A brisk pedal to the Control tower and he is there in less than 15 minutes from the time he spoke to Sam
The control tower of San Francisco Airport is built within the structure of the terminal. After the bombs fell MilGov moved into it as an observation point, but eventually was reopened to most people in the last few years. Fishing fleet spotters, scientists looking at everything from clouds to waves, even just sightseers will climb to use its height to see out into the Bay.
MilGov stil maintains a presence there with a squad of soldiers stationed there at all times and several military observers. They will check papers to allow access. Diego’s status and papers would permit him access. The tower is 120 feet high so you can see at least 20 miles across the bay into Oakland