Runway incursions have been a very hot button issue that the FAA has been very keen on eliminating. 100% of the time they are due to human factors:

1.) Pilot(s) didn't follow ground or tower controller instructions
2.) Ground or tower controller gave wrong instructions to pilot(s)

The FAA will fully investigate this, starting with listening to all relevant tapes. Then, depending on who erred, pilot and/or controller certifications will likely be suspended pending further training/review. If the responsible parties have had previous incursions, permanent revocation is possible. That's a career ending mistake, even if people don't die.