The most popular equipment Merion was not a golf club but a squeegee.

More heavy rain at the U.S. Open flooded a bunker by the 11th green and filled fairways with large puddles and tiny stream. The course was closed for four hours during the first full day of practice, and shut down for good later in the afternoon.

The U.S. Open returns to Merion for the first time in 32 years. And it looks like it will be a wet U.S. Open.

Ernie Els says even if officials had helicopters hover over the fairways, the turf still won't be as firm as the USGA wants it for the toughest test in golf.

And worst might be ahead. The forecast is for more rain on Thursday for the opening round.