On August 14, 2018, a section of the Morandi Bridge that linked the Sampierdarena and Cornigliano districts in Genoa, Italy, collapsed during a torrential rainstorm, sending about 35 cars and three trucks down into the Polcevera river. The cause of the collapse isn’t entirely clear, but it appears that four of the bridge stays had corroded through and failed explosively, possibly set off by a lightning strike. Like many such structural accidents, it came as an almost complete surprise and sparked a political scandal about the state of the infrastructure in Europe.

However, a recent study indicated that the signs of impending collapse were there if it had been possible to see them beforehand. And now it is possible to see those signs after scientists from NASA discovered it is possible to monitor the safety of bridges using satellite radar imaging. Using 15 years of orbital radar images of the Morandi Bridge, the researchers were able to detect signs of warping that preceded its collapse in 2018. According to the NASA researchers, the new technique allows engineers to study an entire bridge in real time rather than relying on the much more limited localized data coming from sensors.

In addition to above-ground structures, satellite monitoring can keep an eye on underground works by measuring the shift in buildings on the surface. As of now, the technique is being considered for use in Britain to monitor road and railway networks.