Chesapeake Energy Corp,the Oklahoma-based firm is the No. 1 driller in Ohio.
Rig Count Interactive Map by Baker Hughes, an energy services company.
Shale Sheet Fracking, a Youngstown Vindicator blog.
The Ohio Environmental Council, a statewide eco-group based in Columbus.
Earthjustice, a national eco-group.
People's Oil and Gas Collaborative-Ohio, a grass-roots group in Northeast Ohio.
Concerned Citizens of Medina County, a grass-roots group.
No Frack Ohio, a Columbus-based grass-roots group.
Fracking: Gas Drilling's Environmental Threat by ProPublica, an online journalism site.
Pipeline, blog from Pittsburgh Post-Gazette on Marcellus shale drilling.
Allegheny Front, environmental public radio for Western Pennsylvania.
There are reports of a major natural gas pipeline explosion in West Virginia, according to numerous news media.
The explosion took place about 1 p.m. near Sissonville north of Charleston.
It produced a major fireball.
The explosion and fires shut down Interstate 77 northbound and southbound.
Several buildings were on fire.
Authorities were checking for injuries or fatalities.
The fire was extinguished about 2 p.m.