It turns out that when a quarter of your infrastructure is damaged, half of it is occupied by the newly-instituted Downtown San Diego Motor Speedway, and the last quarter of it was designed for pedestrians, it's actually really difficult to get rescue equipment on board. They have some. It's California. But you can't actually get excavation equipment from Point A to Point B without waiting for a break in the speeding vehicles.
Espers come in a much more convenient form factor, they're much cheaper to teleport across a street, and they don't require either A: diesel or B: electricity to run.
Which explains why Graviton was requested for San Diego. Her first assignment is one particular building in the northeast section of downtown San Diego that's got a partially-collapsed stairwell and some victims who would really like to no longer be in it.