Narrative:

I was training on local control. Aircraft X landed; I told them to turn left on a taxiway and contact ground. Aircraft Y was cleared to land and on a short final for an intersecting runway. Ground control asked for a crossing. I said hold short. Ground told aircraft X to cross the runway. My trainer reacted quickly and yelled hold short to ground control. At this time aircraft Y had touched down and there was no way to send him around. Ground quickly told aircraft X to stop and hold short of the runway. Aircraft X continued his crossing until realizing he needed to get off the runway. He made a 180 degree turn back; to hold short of 21 at the taxiway.

Google
 

Original NASA ASRS Text

Title: A Tower Controller reported the Ground Controller allowed an aircraft to enter a runway at the same time another aircraft was landing.

Narrative: I was training on Local Control. Aircraft X landed; I told them to turn left on a taxiway and contact ground. Aircraft Y was cleared to land and on a short final for an intersecting runway. Ground Control asked for a crossing. I said hold short. Ground told Aircraft X to cross the runway. My trainer reacted quickly and yelled hold short to Ground Control. At this time Aircraft Y had touched down and there was no way to send him around. Ground quickly told Aircraft X to stop and hold short of the runway. Aircraft X continued his crossing until realizing he needed to get off the runway. He made a 180 degree turn back; to hold short of 21 at the taxiway.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.