On 19 September 1980; routine maintenance on a Titan II Missile almost wiped out the state of Arkansas. A resulting explosion killed one person; and injured 21 more. Broken Arrow refers to incidents involving Nuclear Missiles. There have been 32 in total.
News story below marks the 33rd anniversary of Site 374-7. The other missiles sites listed in the article contain co-ordinates of the other sites. Little is visible; other than a typical circular mound, building foundation and paved access road. The sites have all been de-commissioned and reclaimed.
http://fullcomment.nationalpost.com/2014/03/24/eric-schlosser-stuck-in-a-hole-with-a-leaky-nuclear-missile/