Bill Chappell

Canadian authorities have disrupted an alleged plot that targeted a passenger train line running between New York and Toronto, the Royal Canadian Mounted Police announced Monday. The plan involved derailing a train, but police officials would give few details about the plot at a news conference this afternoon.

But they did say they believe the suspects received support or help from al-Qaida.

Many airline passengers saw only moderate flight delays stemming from the first full day of furloughs for nearly 15,000 flight controllers and other Federal Aviation Administration workers, as industry analysts' worst fears did not materialize. But the reduced staffing was blamed for some slowdowns, and observers say it also increased the length of unrelated delays.

We'll be keeping an eye on possible delays today, and updating this post with new information.

Update at 6:45 p.m. ET. Delays Build, Many Tied To Weather:

Towns in Missouri, central Illinois and at least four other Midwestern states are under a flood warning, as heavy spring rains swell the Mississippi and other rivers to dangerously high crests. In some areas, rivers have already hit record flood levels.

In places where residents have been forced to evacuate their homes, the American Red Cross has set up shelters at schools and other facilities.

Hundreds of Boston-area residents gathered Sunday to pray, to sing and to remember the victims of bombs and other violence in the city this week.

Six churches organized an interfaith service near the intersection of Boylston and Berkeley streets, close to the cordoned-off area where investigators are examining the crime scene created when two bombs tragically altered the finish of the 2013 Boston Marathon.

Boston bombing suspect Dzhokhar Tsarnaev has not yet been questioned — but officials' decision not to read him his Miranda rights before interrogation is the subject of much debate.

(Most recent update: 4:20 p.m. ET)

Investigators are still waiting to interview Boston Marathon bombing suspect Dzhokhar Tsarnaev, whose wounds reportedly include injuries to his neck and leg. An official tells CNN that Tsarnaev has been "intubated and sedated," rendering him unable to speak with them.

The London Marathon observed 30 seconds of silence before the race got underway Sunday, in a show of solidarity with the victims of Monday's attack at the Boston Marathon. Many runners and spectators wore black ribbons to honor the three people killed and the more than 170 injured in two bombings.

Christopher Knight, whose 27 years of living in near-total isolation in Maine's wilderness made him an object of fascination after he was arrested for stealing food and supplies, appeared by video for a court hearing Tuesday, when a Kennebec County judge set his bail at $25,000 cash.

What does it take to ride a bicycle at 100 miles per hour? That's the question being explored by Britain's Donhou Bicycles and frame builder Tom Donhou, who has mounted a mammoth chainring onto a custom bicycle. He says the steel machine has already hit 60 miles per hour on the open road.

News of the deadly bombing attack on the Boston Marathon is echoing in Oklahoma City, where residents will observe the 18th anniversary Friday of the bombing of the Alfred P. Murrah Federal Building, which killed 168 people. The events include a marathon, which remains on the schedule, although officials say they will review their security plans.

Even as the shock and horror of the deadly explosions at the Boston Marathon had yet to subside Monday, people were turning to online tools to check on the safety of their friends and family who were at the event. The latest estimates of the casualties include more than 3 dozen people injured, with two dead.

As has been the case in previous calamities, Google and the Red Cross helped to connect people with runners, spectators, and volunteers who were at the race.

Here are several tools that came into use today:

People near the finish line of the Boston Marathon described horrific scenes of the chaos that followed two loud explosions in quick succession this afternoon, sending spectators rushing away from the scene in panic as others lay bloodied and wounded on the ground.

One witness, Aaron Michael told member station WGBH that he heard first one explosion and then another.

The new batch of Pulitzer Prize winners has just been announced, with novelist Adam Johnson winning the fiction prize with The Orphan Master's Son. The winners of the prizes for Americans' best work in journalism, drama, music, and writing also receive a $10,000 cash award.

Vietnam has sent what analysts believe could be the remains of a member of the American military who died in the country during the Vietnam War. After a repatriation ceremony at the airport in Da Nang Sunday, the remains were sent to Hawaii for examination and possible identification.

More than 23,600 people were victims of human trafficking in Europe during a recent three-year period, according to a new European Union report that says the problem is growing worse. Its authors say the official figures do not come close to describing the crime, which has "hundreds of thousands of victims."

Communications between the Earth and Mars are on hiatus for several weeks, thanks to interference from the sun. That means NASA's orbiters and rovers that study Mars will be left to their own devices until radio signals can once again travel between the two planets.

Known as "solar conjunction," the problem arises when the orbit of planets places the sun directly between them.

The baseball season is still young, but the New York Yankees have already faced harsh public criticism. No, we're not referring to their lackluster record. Instead, the Yanks were accused of trying to hoodwink beer drinkers with a new "Craft Beer Destination" concession stand at their Bronx stadium.

Inmates fought guards at Guantanamo Bay, Cuba, after military authorities decided to end communal housing in one of the prison's camps, and instead put prisoners in individual cells. At least one detainee was reportedly injured by a rubber bullet in the clash Saturday.

The violence began after the facility's commander ordered the move Saturday morning. According to the U.S. Southern Command, the decision was made after detainees covered windows and surveillance cameras, limiting guards' ability to monitor them at all times.