US STOCKS-Wall St slumps amid fall in commodity prices
* Copper prices hit 3-week low, oil down over 2 pct
* All 30 Dow components and 10 S&P sectors down
* Volatility index jumps 15 pct
* Goldman falls after CEO discloses he has cancer
* Indexes down: Dow 1.55 pct, S&P 1.55 pct, Nasdaq 1.80 pct (Adds details, comment, updates prices)
By Tanya Agrawal
Sept 22 (Reuters) - Wall Street fell more than 1.5 percent on Tuesday morning amid a decline in commodity prices and continuing uncertainty about when the Federal Reserve will raise interest rates.
The selloff was broad-based. All 30 Dow components declined. All 10 major S&P sectors were lower, led by a 2.4 percent drop in the materials index and a 1.9 percent fall in technology stocks.
Copper prices hit a three-week low, while oil was down more than 2 percent on persistent worries about demand, especially in China. Continuación...