The investigation into the tragic helicopter crash at the WBIG tower site in Aurora has determined that the lights on the tower were working properly at the time of the accident:

Video shot by a security camera confirms that the warning lights on a radio tower in Aurora were functioning last week when an emergency medical helicopter hit one of the structure’s support wires and crashed, the chief investigator into the fatal accident said Tuesday.

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The video shows strobe lights on the tower blinking, said John Brannen, the investigator-in-charge with the National Transportation Safety Board.

“They cease blinking at the time of accident, 11:58 p.m.,” Brannen said, citing radar data that helped authorities pin down the time.