2 loud, mysterious explosions heard across Brockton accompanied by white flashes of light; Authorities working to narrow down source Updated Dec 28, 2020; Authorities are working to narrow down the source of two loud, mysterious explosions that were felt across Brockton over the weekend and were accompanied by white flashes of light. The explosions were reported shortly before midnight Sunday and were most prevalent on the east side of the city. The flashes of light were documented on social media, according to a Facebook post from Brockton Fire and Life Safety. Some people claimed the explosions were fireworks, while others reported them as something “bigger,” the post said.