SAN DIMAS, Calif. (KABC) -- A brush fire burned several acres near the interchange of the 57 and 71 freeways in the San Dimas area Wednesday morning, according to the Los Angeles County Fire Department.Forward progress of the blaze was stopped at 3 acres near Via Verde around 10:20 a.m., fire officials said.AIR7 HD was over the scene as crews mounted a ground and air attack, dumping 1,000 gallons of water on the fire.Traffic was backed up for several miles as the two right lanes of the southbound SR-57 near San Dimas Avenue were shut down. They reopened a few hours later.It is unclear if any injuries were reported, or if any structures were damaged.The cause of the fire remains under investigation.