Two blasts near the finish line of the 117th Boston Marathon Monday left the city in shock and frenzy. Soon after, disheartening on-the-ground tweets, photos and videos were shared throughout the social web. In the early hours, these updates served to inform the entire world of the horror and tragedy transpiring through the streets of Boston. In the later hours, online and social media tools such as Google Docs and Twitter connected Boston locals to the out-of-town runners and visitors who could really use their help. The way social media is manifesting in immediate relief for victims is perhaps one uplifting moment in a truly heartbreaking day. WARNING: Some graphic images are in the roundup below.

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