CLEVELAND, Ohio -- The Cleveland Hopkins Airport worker who drove an SUV across an active runway Sunday was leading a team of snowplow operators - some of whom followed him onto the runway as a commercial flight was taking off.

Cleveland Director of Port Control Fred Szabo said in an interview Friday that the SUV driver was heading up a pack of snowplows clearing a parallel runway that had been shut down at about 12:30 a.m.

When the worker drove his SUV across the active airfield -- ignoring a series of lights and barriers alerting him to the danger of departing flights -- some of the other drivers followed "before they recognized what had taken place," Szabo said.

The director declined to say how many plows were involved in the "incursion," citing an ongoing internal investigation of the incident. (Click on the video above to hear an audio recording of the air traffic control chatter of the incident.)

On Thursday, Szabo said the SUV passed below an aircraft - now known to have been a Spirit Airlines Airbus A320 -- as it became airborne. That model aircraft can hold up to 150 passengers, according to Airbus' website. Cleveland.com is still trying to determine how many passengers were on board the Spirit flight in question.

Szabo said Friday that one Southwest Airlines flight was delayed on its descent while the airport ensured that no further runway hazards remained.

Szabo maintains that the runway incursion was an isolated incident -- boiling down to the "judgment of one person." He said the driver in question, a 13-year veteran of the airport staff, was immediately ordered off his shift and remains on administrative leave. Szabo added that the traveling public should have no reason to doubt the safety of the airport's runways.

A spokeswoman for the Federal Aviation Administration on Friday said the agency is investigating the matter and still has not determined how close the SUV came to the departing flight.