Oil prices plummeted Tuesday in Asia, falling briefly below $92 a barrel, the Associated Press reported. Light, sweet crude for October delivery tumbled $3.59 to $92.12 a barrel in electronic trading on the New York Mercantile Exchange midafternoon in Singapore. It briefly fell as low as $91.54. Overnight, the contract dropped $5.47 to settle at $95.71, the first time oil closed below $100 since March 4. In other Nymex trading, heating oil futures fell 8.12 cents to $2.71 a gallon, while gasoline prices dropped 7.28 cents to $2.4886 a gallon. Natural gas for October delivery fell 5.2 cents to $7.322 per 1,000 cubic feet. In London, October Brent crude fell $1.63 to $90.70 a barrel on the ICE Futures exchange.