OSCAR-winning actor Sean Penn's well-intentioned attempt to save children from the floods of New Orleans, Louisiana, failed miserably when his decrepit boat started leaking dangerously.

The MYSTIC RIVER star, who was desperate to do "whatever I can to help", reportedly forgot to fix a hole in the rescue vessel, which promptly started sinking as he furiously scooped water out of the boat with a plastic cup.

Penn allegedly attracted criticism from onlookers when they saw the boat was already crammed with Penn's entourage - including a photographer - before any flood victims climbed onboard.

One onlooker said, "How are you going to get any people in that thing?"