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What: Shares of ON Semiconductor (Nasdaq: ONNN) are plunging today, down 13% at the low, as the company provided an update on the impact of floods that have hit Thailand.

So what: The company has suffered damages at its plant in Rojana Park in Thailand, which will weigh on results over the next year due to restoration expenses. The Sanyo Semiconductor unit and Bang Pa In facility are estimated to hit revenue to the tune of $40 million to $60 million over the next three or four quarters.

Now what: Operations at affected plants have been suspended indefinitely, since the floods have prevented access to the facilities. The Rojana Park operations contributed roughly 10% to 12% of the company's revenue in the second quarter. Although the company has insurance, damages could exceed the $50 million in potential proceeds from insurance claims. The one bright spot in the situation is that the flooding caused no on-site injuries to any of the company's employees.

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