When the game was cancelled just before kick-off in the west German city, hundreds of Monaco supporters found themselves with valid tickets for the rescheduled match the following day, but with nowhere to spend the night.
Their dilemma prompted Dortmund fans to initiate the #bedforawayfans hashtag on Twitter as a way to offer overnight lodging to the stranded fans.
A social media strategy that worked: the hashtag quickly began trending on Twitter, and some Monaco fans took up the offer. Several Dortmund fans posted pictures on the social media site of themselves hosting Monaco supporters in their homes, with some tweets being liked and retweeted thousands of times.
The official Twitter account of Borussia Dortmund encouraged the away fans to check out the initiative.
AS Monaco also applauded the effort via Twitter: "Das ist Fussball!"
The hashtag additionally earned praise from French and German media.
“All together! Solidarity has developed between the fans of both teams,” wrote French sports newspaper L’Equipe.
Rolf Fuhrmann, German Sky sports reporter, tweeted: “#bedforawayfans Dortmund & Co, you are all simply brilliant”.
Three explosions hit the Dortmund bus as it was on the way to the stadium for Tuesday's Champions League match. Defender Marc Bartra was injured by shards of glass.
German police, who have said they are investigating all possible leads including terrorist links, announced on Wednesday they had detained a suspect.
"Two suspects from the Islamist spectrum have become the focus of our investigation," said lead prosecutor Frauke Koehle. "Both of their apartments were searched, and one of the two has been detained."