Line Breaks for ALT=TEXT

Is it possible to force a line break or carriage return when 
using the ALT= attribute for images? I've tried imbedding <br>'s or
forcing <pre>'s, but that doesn't work.

I want to force the line break because in some instances, providing lengthy
text descriptions of an image for the visually impaired is required. However,
from a visual appearance, the test flies right off the browser window.

Thanks,

Mike Paciello
WebABLE Design Associates
http://www.webable.com