Update: 2:30 p.m.: The AP reports that the ground stop has been lifted. However, according to FAA deputy assistant administrator Laura Brown, air controllers are now working from an alternate location.
Previously 2:15 p.m.: A ground stop was put in place at Newark Liberty International Airport in New Jersey after smoke was reported in the elevator shaft of the airport's Air Traffic Control tower, reports the Associated Press.
The tower has been evacuated, MSNBC reports. Watch the video above.
More details as they become available.