1. Structural Engineer-in-Training, DIALOG, 1100, 2 Bloor St. E, Toronto, ON, Canada M4W 1A8.
2. Bahen/Tanenbaum Professor, Dept. of Civil Engineering, Univ. of Toronto, 35 St. George St., Toronto, ON, Canada M5S 1A4 (corresponding author).
3. Director, Explora Security Ltd., 3–4 Talina Centre, Bagleys Ln., London SW6 2BW, UK; Adjunct Professor, Dept. of Civil Engineering, Univ. of Toronto, 35 St. George St., Toronto, ON, Canada M5S 1A4.
4. Professor, Dept. of Civil Engineering, Monash Univ., Clayton, VIC 3800, Australia.