A dump truck smashed into a pedestrian bridge on a busy highway in northern Rio de Janeiro Tuesday, causing the walkway to collapse onto three cars and a motorcycle below. At least four people were killed in the accident, authorities said. Another four people were injured, according to Lamsa, a private company that administers the toll road. According to AP, witnesses said that there were only two people on the yellow metal pedestrian bridge when the accident occurred just after 9 a.m. Normally it would be crowded at that hour, but is in less use because of Brazil's summer holidays. Mayor Eduardo Paes told reporters at the scene that the trailer of the truck was clearly above the 4.5 meters (14 1⁄2 feet) permitted for use on the highway, known as the Yellow Line road, which cuts through gritty northern and western portions of Rio.