Fuel Leaking at start up

My 2001 Passat (4 cylinder) had been sitting for 3 days in 100 degree weather (don't know if that matters). I started it and turned on the AC. I got out to let my Dog in the car and noticed fuel leaking right near the rear passenger side wheel. It looked as though it was coming from the rubber gas line connecting the fule line to the fuel filter. Once the car warmed up, it stopped leaking. I then drove it 400 miles and got typical 26 mpg. What might be causing this? It happened again this morning, but only at start-up. Stopped when it warmed up. Any insight anyone can provide would be helpful.

It could be alot of things, loose/damaged hose, fittings...get it fixed.

I am pretty sure that the fitting on the hose nearest the fule filter was loose. I tightened it and the leak stopped. Pretty basic, I guess.

Thanks.