<http://schema.org/caption>
"This photo was taken on July 8, 1927 in Vulcan, Alberta, Canada. Here you can see the tornado closing in on the city."^^<http://www.w3.org/2001/XMLSchema#string>
<http://www.4029tv.com/article/majestic-monsters-tornadoes-captured-over-the-years/4913336>