Feb 07, 2010. Gas explosion in Middletown, CT kills 5 and injures 26. An accidental gas explosion occurred around 11:15 am at the Kleen Energy plant in Middletown, CT. While New England Seismic Network (NESN) sensors often record small mining explosions and construction blasts, we did not record any significant seismic signal for this event. It is very likely that most of the energy of the blast went into the air (hence it was widely heard) and did not couple well into the ground. A map of communities that reported feeling the blast (see link below) shows an interesting gap where no felt reports were made. This may be indicative of the weather and hence the atmospheric conditions (temperature and wind) at the time of the explosion, as they control the propagation of acoustic waves in the atmosphere.

Map of Middletown Explosion Felt Regions

Nov 22, 2006 Danvers explosion. A large explosion at a Danvers printing plant at 02:46 am EST destroyed a block of houses surrounding the plant. The explosion was easily detectable at Weston Observatory, approximately 50km away. The force of the explosion was equivalent to a magnitude 0.5 earthquake.
Click to Read a Boston Globe article about the accident
Click to see the seismic recording of the explosion at Weston Observatory