OKLAHOMA CITY - The southbound side of Interstate 235 was completely shut down due to an injury involving a fire department vehicle.

As of 4:40 p.m. traffic was open in two lanes, but still moving slowly and backed up for miles.

Emergency crews were called to the scene on SB I-235, just north of I-40, involving four civilian vehicles and an Oklahoma City Department truck. At least one person suffered an arm injury in the crash. It is unclear if anyone else was injured.

The cause of the crash is under investigation.

Keep checking with News 9 and News9.com for more information.