fuel line leak
My car has seemed to develop a serious gas line leak. I had gone to the store my wife works at to pick up a few items, and when I came out, there was a huge puddle of gasoline under it. I was afraid to drive it home like that with the baby, so I took my wife's car. I will pick it up tonight when she gets off, so the baby does not have to ride in it. The leak is close to the exhaust, I'm somewhat concerned about a fire.
I looked under it in the parking lot, and it seems to be leaking from somewhere above the differential. I have to borrow a jack and jack stands, so I won't be able to get under it and really see what's going on until the morning. My question is, what are the possible causes of this? Could it just be a line leaking, or maybe the tank? How does the line connect to the tank? How hard of a fix would it be? I assume it's a metal line, so if it's leaking, will I have to replace the line all the way from the tank to the fuel pump?
I'm sorry about not knowing more about the problem, I'm just trying to get some ides right now. The car is a '73 Chevelle, 350/350. The tank and lines up to the pump are all original, as far as I know. Thanks in advance for any help.