FireRescue1 is reporting:

HOUNSFIELD, N.Y. — A fire in an animal-feed silo triggered an explosion that killed a firefighter at a farm in northern New York where, just three days earlier, a barn blaze killed more than 100 cows.

Authorities say they believe the barn fire Thursday night at North Harbor Dairy Farm in the town of Hounsfield, 60 miles north of Syracuse, might have kindled the explosion at the nearby steel silo Sunday. 

Read the full article at:

http://www.firerescue1.com/volunteer/articles/805917-Silo-explosion...

In the comments section after the article is the following response from a read:

Gentlemen and ladies reading this...

Listen up:

It is the year 2010 for Gods sake.

Q1: Why was a firefighter even on a silo that was involved in fire?
Q2: Better still why was an assistant FIRE CHIEF on the silo that was on fire?
Q3: Why would anybody, in this day and age, with all the knowledge, and procedures and experience and equipment and fire science we have at our disposal, especially for the last twenty years, even get on the top of any structure, that is on fire?

There's some food for thought here, me thinks....

Someone in the video (on the linked page) also says that explosions are unusual, but in reality, they're not. There's some very real hazards with silos, dust, fire and explosions.

Go and search SILO EXPLOSION on YouTube and see what pops up....