TY - GEN AU - Grill, Raymond A AU - Johnson, Duane A C2 - , National Institute of Standards and Technology, Gaithersburg, MD DA - 2005-01-01 05:01:00 DO - https://doi.org/10.6028/NIST.NCSTAR.1-1h LA - en PB - , National Institute of Standards and Technology, Gaithersburg, MD PY - 2005 TI - Post-construction modifications to fire protection and life safety systems of the World Trade Center towers: ER -