One of our biggest saguaros at home was struck by lightning last Saturday night during a monsoon thunderstorm. It was hit at the base, leaving a seared entry, and blew out a big section of the cactus on the opposite side [left]. The next day, the top 8 feet of the 20 foot high plant, snapped off. [right, before the top section snapped off. Note the debris on the driveway from the strike.]
I've been on the road since then but my wife Ann took lots of photos that I finally saw tonight. The whole cactus is tilting so I temporarily braced it with 2x6's until we see if it's going to survive. If it falls across the driveway, it's going to be a challenge to move the estimated 2-4 tons it weighs.