The Boston Marathon is considered the pinnacle of marathon running in the U.S., but today, when the 117th Boston Marathon took place, the finish was marred by a terrorist attack that occurred near the finish line.

The 2013 Boston Marathon was officially won by Lelisa Desisa Benti in the Men's Division and Rita Jeptoo in the Women's Division. Soon after the marathon winners passed the finish line, a series of explosions occurred near the end of the race course. The explosions were filmed by several bystanders including journalists and civilians. Footage of 2013 Boston Marathon explosion is gruesome and startling. It also depicts the level of hysteria that surrounded the event after the explosions went off

The 2013 Boston Marathon terrorist attacks were captured in significant detail from cameras used by the media to capture the end of the race. Among all the cameras that were able to capture footage of the explosions, the Boston Globe was able to capture one of the most unique angles of the first explosion. The Boston Globe deployed a camera to capture runners as they passed the finish line, but as the camera was collecting B-roll footage, an explosion happened at the north side of Boylston Street in downtown Boston. As the explosion hit, dozens of people screamed and several runners continued to jog past the gigantic plume of smoke. The Boston Globe reporter, who has been unidentified, ran with his camera toward the explosion. "We've had an attack," he whispers into the camera.

The 2013 Boston Marathon explosion reportedly caused two deaths and left more than two dozen people injured. There were two explosions that occurred on the course of the Boston Marathon itself, and later in the evening, just before 4 p.m., another explosion reportedly occurred at the JFK Library. "Eyewitnesses said the explosions were about 15 seconds apart. A few runners stopped and turned around after they heard the blasts. Some runners were seen crying and some said they saw limbs on the ground," reports the New York Times.

The Boston Marathon bombing suspect still has not been identified by any major media outlets. A Saudi-Arabian man, 20, was reportedly identified as a suspect and was apprehended by law enforcement officials. Law enforcement officials told the New York Post that the 20-year-old man was being guarded at an undisclosed hospital. Although the New York Post reported extensively on the Saudi suspect, most other major news organizations reported that the NY Post report was inaccurate. Twitter users clamored for photos, footage and film surrounding the event, and images such as this one surfaced, but very few were ever confirmed as real. Details surrounding the 2013 Boston Marathon attacks are still murky.

Boston police commissioner Edward Davis denied reports about anyone being detained as a possible suspect. "Those reports are not true, there is no suspect in custody," Davis said at a press conference.

U.S. President Barack Obama was also unwilling to speak about who is suspected to be behind the attacks. He also did not answer questions about whether the event would be considered an act of terrorism. "We don't know who did this or why. And people shouldn't jump to conclusions before we have all the facts," Obama said. "But make no mistake, we will get to the bottom of this. And we will find out who did this, we'll find out why they did this. Any responsible individuals, any responsible groups will feel the full weight of justice."

Terrorism experts believe that an organization or someone with extensive knowledge of bomb construction was likely behind the attack. "This is the kind of attack that is calculated or linked to an event," said Bruce Hoffman, director, Center for Peace and Security Studies at Georgetown University, in a Discovery News report. "That means whoever did it wants attention. There will be some kind of claim of who is behind it."

Until the Boston police commissioner or U.S. President confirm the person or people behind the Boston terrorist attacks that took place at the 2013 Boston Marathon, it's unreasonable to assume that any specific person or entity is responsible for the attacks. Images such as this one have surfaced across social media sites indicating that a person was on the roof a building near the first explosion. Authorities have not confirmed the detainment of any suspects and have made very few comments about who they believe were behind the attacks. We'll keep you posted as more information becomes available.