The truck driver was waiting at a stop light on the way from a warehouse operated by the Northgate Market grocery chain to one of its stores when the Union Pacific train struck its trailer, Northgate distribution manager Sal Marcianti said.
Marcianti said the company was investigating.
"Maybe he thought he had cleared the track, but apparently there was a foot of the trailer hanging over the track," he said.
The driver was not injured, but the crash destroyed about $20,000 in merchandise, Marcianti said.
Crushed cartons overflowing with bananas, avocados and vegetables littered the area.
Union Pacific spokeswoman Zoe Richmond said the company would use video of the crash recorded by a camera on the train's locomotive to investigate the incident.