At about 8pm Sunday night in Portland, Oregon a large explosion was heard by many people. Geo-developer Reid Beels quickly set up a Google My Map so that people who heard the explosion could show their locations.
Using the open collaboration setting in Google My Maps he allowed people to add coloured map markers to the map to say whether they heard the explosion or not. Red markers meant they 'heard a loud boom, windows or building shook', blue markers that they 'heard it, but no further detail', yellow indicates it was 'heard with no shaking' and green indicates the explosion was not heard.
The clustering of the markers soon suggested that the explosion originated near Sellwood Bridge. Using the map the police were able to pinpoint the location of the explosion and discover that it was caused by a detonated pipe bomb.