During our performance of Niagara Falls today, I really got into those ffff glissandos on the last two pages. A few measures into the final stretch, things suddenly felt off and I realized I was hitting a space where a string had broken. I broke both the 2d octave D and E on one particularly “issimissimo” gliss. Our conductor is very fond of the piece so I gave him the strings as a souvenir, as soon as our assistant conductor was finished using them as bug antennae.