PNG SVG PSD EPS MORE
Signs
Flat
Alerts
warning, Signaling, Attention
Tomato
512x512
Construction
warning, Attention, Error
Web and Apps
Close, cancel, Error
Computer
Computer security set
malware, Computer, virus
Multimedia Rounded Icons
cancel, Error, signs
PNG ICO MORE
24x24 Free Application
warning, wrong, Alert
24x24
PNG ICO ICNS MORE
Farm-Fresh Web
Alert, wrong, warning
32x32
Tango
Alert, Dialog, Error
WP Woothemes Ultimate
stop, no, exclamation
256x256
PNG ICO ICNS SVG MORE
Files & folders
small-n-flat
Error, sign
Mixed
Smooth
Tango Icon Library
Error, Dialog
Business & finance
Glyph
48x48 Free Time Icons
Abort, exclamation, Up
48x48
PNG MORE
24x24 Free Application Icons
Error
Network & communications
Pixel
16x16 Free Application Icons
16x16
Music & multimedia
Simple
drive, Error, failure
128x128
Computer & hardware
3D
Discovery
Desktop apps
Free Applications Icons
Alert, exclamation, General
UI
infomation, worning, Dialog