Have you been reading my mind?
The map I'm working on is similar - a power plant is leaking toxic ooze down into a populated area. Survivors must carry gas canisters to each of the generators. Once the generator has gas, it can be started (which will take a minute or two, where it has to be protected). Once ALL generators are started, power is converted to a large elevator which the survivors must wait for, then use to escape.
Not the most original idea, but it might be cool.
