Beau Biden, Delaware attorney general, and son of vice president Joe Biden, was scheduled to appear in Iowa City this morning for a veteran-to-veteran phone bank in support of President Barack Obama.

Then a tragedy occurred in Colorado.

A lone gunman entered an Aurora, Colorado movie theater early this morning and opened fire on the audience at a Dark Night Rises showing, killing 12 people and injuring dozens more.

The shooting has already had far reaching effects across the nation, even in the political arena. The Obama campaign decided to cancel several campaign events scheduled for today, and to pull its negative advertising running in several states until next week.

These events included the event by Biden.

"In light of the tragedy in Colorado, the event in Iowa City has been cancelled. We apologize for the inconvenience," wrote Obama in Iowa spokesperson Elizabeth Purchia, in an e-mail about the event's cancellation.

Here is a link to remarks made by President Obama regarding the shooting.