In a worst-case scenario, the June 21 Philadelphia refinery explosion could have released a cloud of deadly hydrogen fluoride gas that could travel for seven miles and threaten more than a million people.

"The Trump administration has quietly dismantled or cut back multiple programs that were created after the Sept. 11, 2001, attacks to help detect and prevent terrorism involving weapons of mass destruction, a Times investigation has found."

"Two thirds of the United States is expected to bake under what could be record high temperatures heading into the weekend. ... But people with health issues, older people and young children are especially susceptible to the effects of extreme heat. It’s a threat that grows as climate change continues."

"A new report by staff members of the Nuclear Regulatory Commission, which oversees the safety of the nation’s 59 aging nuclear power plants, recommends that the commissioners significantly weaken or reduce safety inspections of the plants."

"Climate change caused the increase in size of wildfires occurring across California in the last 50 years, according to a new study published in this week's journal Earth's Future.

Since the early 1970s, California wildfires have increased in size by eight times, the study says, and the annual burned area has grown by nearly 500%.

"Fewer mock commando raids to test nuclear power plants’ defenses against terrorist attacks. Fewer, smaller government inspections for plant safety issues. Less notice to the public and to state governors when problems arise. They’re part of the money-saving rollbacks sought by the country’s nuclear industry under President Donald Trump and already approved or pending approval by the Nuclear Regulatory Commission, largely with little input from the general public."

"A heat wave featuring a life-threatening combination of heat and oppressive humidity has begun to spread across the United States, with excessive heat warnings and heat advisories in effect for at least 22 states and the District of Columbia."

"New research shows that the extreme weather and fires of recent years, similar to the flooding that has struck Louisiana and the Midwest, may be making Americans sick in ways researchers are only beginning to understand."

"Recent California earthquakes that rattled Las Vegas have shaken up arguments on both sides of a stalled federal plan to entomb nuclear waste beneath a long-studied site in southern Nevada."

"Communities in Louisiana are taking the first steps toward recovery after Hurricane Barry made landfall in the state as a Category 1 storm Saturday before being downgraded to a tropical storm."