Boston bombing. Ricin in D.C. Texas inferno. Any links?

Boston bombing case has no suspect or suspects, which has opened the door to speculation. But the fire in Texas appears to be happenstance, and an arrest has been made in connection with the poison-laced letters.

Deadly bombs at the Boston Marathon. Poison-laced letters sent to President Obama and Capitol Hill. A Texas fertilizer plant explosion so massive it registered on the Richter scale.

Bad news has piled up fast in recent days. It’s tempting to look for clues that link the events together. As Politico’s chief political columnist Roger Simon tweeted on Wednesday night, “Conspiracy theorists gonna have a field day tomorrow.”

But it’s worth pointing out that at this point, there is no evidence that Boston, ricin, and West, Texas, are related in any way.

Beginning with the latest development: To all appearances, the Texas tragedy was happenstance. A fire started in one part of the West Fertilizer Co., and local firefighters responded to try to put it out. A few minutes later, the fire lit some of the large quantities of ammonium nitrate fertilizer that's produced and stored at the plant. At high temperatures, this common substance becomes a powerful explosive.

“Based on what I’ve heard, it’s probably an industrial accident of some sort,” said Rep. Bill Flores (R) of Texas Thursday morning during an appearance on CBS.

Unintended ammonium nitrate explosions are uncommon but not unknown. Since 1921, at least 17 such explosions have produced casualties, according to The Washington Post’s Wonkblog.

Six of those were in the United States. The worst occurred in 1947, when a fire aboard a ship docked in the port of Texas City blew up 2,300 tons of ammonium nitrate cargo. Five hundred eighty one people died, including most of the town’s fire department.

“It still ranks as the deadliest industrial accident the country has ever seen,” Wonkblog’s Brad Plumer writes.

Meanwhile, the man who allegedly mailed letters laced with the potent toxin ricin to the White House and to congressional offices is now in custody. His name is Paul Kevin Curtis, he’s from Corinth, Miss., and he seems a very unlikely conspiracy participant.

He apparently made little effort to cover his tracks. The letters were signed, “This is KC and I approve this message.”

Mr. Curtis is something of a conspiracy theorist himself. In 2000, he sued a Mississippi medical center that had fired him, saying he was terminated because he had uncovered a Mafia-like body parts trafficking ring.

In recent years, Curtis appears to have made a living, or at least some money, as an impersonator of celebrities, including Elvis Presley and Hank Williams Jr. A number of videos of his performances are available on YouTube.

“Prepare to update your profile of domestic terror suspects to include Elvis impersonators who fear criminal gangs of organ-harvesters,” writes The Atlantic Wire’s Philip Bump.

Finally, in Boston the fact that no suspect or suspects have been identified and no person or group has claimed credit for the bombings has opened the door to speculation of all sorts. In such a vacuum, it’s perhaps easier for conspiracy theories to gain ground.

However at this point, many of those conspiracy theories differ and in some cases contradict each other.

Over at Foreign Policy, blogger J.M. Berger has read the reactions of a variety of extremist websites to the bombings (so we don’t have to). Some white nationalists blamed militant Muslims right off, he says, while others have argued at length as to whether Muslims or Jews are responsible. And a scattering have simply pointed fingers at people with skins darker than themselves.

A few online Islamist jihadists have blamed US gun enthusiasts, while others appear to hope that the perpetrator does turn out to be a foreign terrorist.

“But even they were hesitant, having been burned not that long ago with a premature declaration of responsibility for the actions of [Norwegian mass murderer] Anders Breivik, who embarrassingly turned out to be an anti-Muslim terrorist,” Mr. Berger writes.