Researchers in Italy have warned that Michelangelos David is at risk of toppling, and they say its ankles are to blame. The celebrated marble sculpture, housed at a museum in Florence, stands at about 17 feet and weighs over 12,000 pounds. Its remained largely intact for more than 500 years, but tiny cracks in its ankles may threaten its stability, according to recent findings from Italys National Research Council (CNR), published in the Journal of Cultural Heritage. Experts have long said that David is at risk of collapsing due to the poor-quality marble that Michelangelo used, as well as its precarious pose.