Trading on the Philadelphia Stock Exchange was halted at 11:05 a.m. Tuesday due to smoke in the building.

All employees were safely evacuated from the building, FoxBusiness reported. Essential staff is being relocated.

The Philadelphia Fire Department hasn't determined the origin of the smoke.

All other NASDAQ OMX trading systems are operating normally.

The smoke has been cleared from the trading floor. All member firm employees have been asked to return to the floor to resume trading.

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