First came the fire, then the blast. Assuming the EMS reports are correct, a terror attack on U.S. soil is responsible for only the second-largest mass-casualty event this week. Dwell on that.

Unbelievable:

West EMS Director Dr. George Smith says as many as 60 or 70 people died and hundreds were injured Wednesday night in a fertilizer plant explosion in West.

A rescuer earlier said he knew of five deaths.

Meanwhile, emergency crews were pulling back late Wednesday night because of concerns about the possibility of a second explosion…

The fire started in an anhydrous ammonia tank and spread to the building, authorities said.

It gets worse and worse. More than 60 people are in the hospital, 44 in serious condition. Among the dead, per CNN, are five firefighters and one cop. The explosion apparently sent fire onto the local middle school and … a nursing home. I’m afraid of what I’ll see when I open up news websites in the morning.

If you’re having trouble imagining how big a blast is needed to do that sort of damage, here you go. No one dies on camera but the video’s profoundly distressing, needless to say. Proceed with caution.

Update: Another vivid gauge of the power of the explosion.

Apartment near explosion in #West pic.twitter.com/YAaOR3YOs7

— ron corning (@roncorning) April 18, 2013

Update: If you’re up late and following this overnight, stick with the Houston Chronicle, the Dallas Morning News, KHOU, and KWTX for updates. From the DMN:

“It was a small fire and then water got sprayed the ammonia nitrate, and it exploded just like the Oklahoma City bomb,” said Jason Shelton, a clerk at the Czech Best Western Hotel in West. “I live about a thousand feet from it and it blew my screen door off and my back windows. There’s houses leveled that were right next to it. We’ve got people injured and possibly dead.”…

Bill Bohannan, who told the Waco Tribune-Herald he witnessed the devastating blast of the explsion while visiting his parents.“Every house within about four blocks is blown apart,” he said.

A horrible thought: This may end up being worse than the Texas City disaster.

Update: CNN says a hospital nearby in Waco has been told to prepare for at least 100 injured patients. This is a sharp, and dispiriting, point too:

https://twitter.com/timothypmurphy/status/324737238137176064

Update: You’ve got to be kidding. There’s also a fire at a tank battery in Oklahoma City that’s threatening a propane tank — and it was caused by a lightning strike.

Update: At least 200 people injured, says ABC, and 40 are critical. Help from the Red Cross and state agencies is on the way, but in the meantime local first responders are so overwhelmed that cops are carrying some of the injured to the ER in the back of their squad cars. The local football stadium’s being used as a triage center.

Update: Mercifully, the early EMS report appears to have overestimated the death toll. Officials now say five to 15 people are dead and that 160 are injured.