Mumbai, June 13 -- India's stock market fell 1% on Thursday, hurt by renewed geopolitical tensions between Israel and Iran, and volatility ahead of the weekly Nifty futures and options (F&O) expiry. A London-bound Air India plane crashed soon after taking off from Ahmedabad, further denting investor sentiment. The Nifty 50 closed 1.01%, or 253 points, lower at 24,888.20 on Thursday, its steepest decline since 20 May. Meanwhile, the 30-share Sensex fell 1%, or 823 points, to settle at 81,691.98. The market sell-off was broad-based, with the Nifty Smallcap index falling 1.44% and the Nifty Midcap index closing 1.6% lower. The texture of the market also appears bearish for now as Nifty saw a heavy build-up of calls. The fall in the Nifty 50 in...