Dow tumbles 600 points as oil's historic plunge worsens

US stocks slid further on Tuesday as oil continued to trade below $5 a barrel.
West Texas Intermediate crude contracts expiring in May traded as low as -$16.74 a barrel on Tuesday before trading at $4.25 around midday. June contracts slipped as much as 42%, to $11.89, amid the turbulence.
Stock futures erased premarket gains after reports said the North Korean leader Kim Jong Un was in critical condition following surgery.
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US stocks plummeted on Tuesday amid