A massive blast heard across Paris on Wednesday morning briefly caused panic as residents reported buildings shaking and windows rattling. Police in the French capital quickly confirmed that the noise was made by a fighter jet breaking the sound barrier, and asked people to stop calling the emergency line. Local media later reported that the jet was scrambled to escort a civilian aircraft that had lost communication. The blast was caught on the official video of the French Open just as German Dominik Koepfer was set to serve to Swiss Stan Wawrinka. The players momentarily paused and resumed play. Parisians are already on edge after a stabbing incident near the former Charlie Hebdo offices last week.