A more recent example was the 2013 Boston Marathon bombing, in which mobile network service was so degraded by people checking on the safety of friends and family (or reporting their own status to others) that journalists and the public both assumed that the networks had been shut down to prevent further remote detonations, although this was not the case with any mobile phone company.
Access-class barring is one solution in such a situation, allowing public safety (PS) personnel such as emergency responders to have priority on the network, as well as general emergency calls to public-safety answering points (PSAPs).
The gathering in Washington, D.C. for the 2009 U.S. Presidential Inauguration of Barack Obama also created a MCE.
In this case, network overload was avoided by deploying multiple cell-on-wheels (CoW) units with their own wireless backhauls.
This was a particularly major situation for cell carriers because many attendees wanted to be live on the phone (via voice call or video chat) with others who could not attend the ceremony, further increasing network usage.