I was just walking and game crashed suddenly so I have no steps to reproduce or even clue what has happened. Attaching crash report.
Environment
OS: Windows 7 (ver 6.1, arch x86)
Java: 1.7.0_51 (by Oracle Corporation)
Launcher: Minecraft Launcher 1.3.11 (bootstrap 5)
Minecraft: 14w18a (updated Wed Apr 30 12:25:35 CEST 2014)
Duplicate of MC-54008