PNG ICO MORE
24x24 Free Application
warning, wrong, Alert
Tomato
24x24
PNG ICO ICNS MORE
Farm-Fresh Web
Alert, wrong, warning
32x32
Tango
Alert, Dialog, Error
WP Woothemes Ultimate
stop, no, exclamation
256x256
Business & finance
Glyph
48x48 Free Time Icons
Abort, exclamation, Up
48x48
Desktop apps
Smooth
Farm-fresh
exclamation
PNG MORE
3D
Free Applications Icons
Alert, exclamation, General
Signs & symbols
34aL volume 3.2 SE
Message, exclamation, warning