Hi Lee,
It appears to me that the strong dollar was the main culprit responsible for crude's clubbing today. That's the same take as 'analysts' quoted in this news clip from this afternoon as well:
Oil's steep drop tied to rising dollar ( CL1N EURUSD ) (by Dawn Lim)
NEW YORK (MarketWatch)-- The sharp selloff in oil prices Wednesday was mostly due to the rise in the U.S. dollar, according to energy analysts. "With the euro so weak and dollar so strong, there is a sense that the tremendous strength of the dollar will affect oil," said Tariq Zahir, managing member of Tyche Capital Advisors. "We're seeing a lot of risk-off trade," said Zahir, referring to a broad exit from investments known as risk assets, or the commodities, stocks and currencies that had rallied sharply between 2009 and 2011 along with a rebound in the global economy. July crude (CL1N) closed at $94.81 a barrel, down $4.56, or 4.6%, as the dollar [S: EURUSD] rose more than 1% against the euro on the back of fears about a Greek debt default. Crude is priced in U.S. dollars and is worth less when the dollar rises. For oil, "the sentiment is bearish once you break $95" a barrel, Zahir said.