One person seriously injured after two car crash on I-95 in Middelsex County.

At least one person has sustained life-threatening injuries after a serious crash on Interstate 95 in Lexington.

The crash happened on the southbound side of the highway, near the Burlington Mall.

A red pickup truck came to rest on its side in the middle of the highway. A white sedan also appears to have been involved.

State Police tweeted a photograph of a blue mattress in the middle of the highway. There’s no word on whether that mattress caused the accident.

The left lane remains open but traffic is backed up.