The distribution infrastructure for distances above a few hundred meters(yards) typically uses 10 or 30 kV, and the former is fairly easy for pantograph-powered

The distribution infrastructure for distances above a few hundred meters(yards) typically uses 10 or 30 kV, and the former is fairly easy for pantograph-powered locomotives. So if the locomotive can optionally use a pantograph instead of it's diesel (tunnels and urban areas on the east coast come to mind), it has a transformer between the low-voltage traction motors / diesel generator rail and the pantograph rail (15~25 kV, typically). The alternator and transformer don't care about the lower voltage, except that their current capability won't change much (so you loose power capability). So I'd assume they should be able to use existing power lines from the other side of the overpass to the school, possibly after isolating that segment from the rest of the grid. This might also connect some other buildings, but typical transformer ratings here (DE, urban, residential; are a few hundred kVA. So (If you don't know what kVA means, "kW felt by wires/ transformer/generator, but not the diesel" is a rough summary sufficient for this scenario. (Don't worry, it's neither wrong nor misleading. If you disagree with that statement, elaborate and feel free to downvote.))