<html> <head> <style> div:first-letter { float: left; background: orange; } /* Note: there's an upper-bound on widths that trigger a crash. This bound depends on the width of the characters in the div. */ div#v { -moz-column-count: 2; width: 30px; height: 1em; background: lightblue; } </style> <script> function boom() { var v = document.getElementById("v"); // Note: This seems to crash regardless of what the text node is; // e.g. it can be the empty string, a space character, or any number of // other characters. v.appendChild(document.createTextNode("CRASH")); } </script> </head> <body onload="boom();"><div id="v">a b</div></body> </html>