Security?
What type of security does the convention center have in Houston? I would ask the police dept. how many thefts have taken place in the lot. You may have a case against the convention center if there are significant thefts.
Do they have camera's on the lot. I'm sure that for a few dollars from all vendors, the convention center could hire a police officer on bike to patrol the vendor area. I suspect that the thieves were not after your quilts and quilting tools, but rather the nice trailer. Do trailer's have a Vehicle number on them somewhere, perhaps the manufacturer could tell you if there was a number stamped on it? I would not attend this show unless the city/convention center pays for extra security, have cameras or have a more secure area for vendors only.
I am so sorry for your loss and emotional upset. Most of us have had this happen at one time or another. Something else you need to be aware of. In Texas back when Ann Richards was our governor, she changed the theft law that makes vehicle breakins a misdameanor rather than the felony that it used to be.....no one has offered to change this law since Ann Richards served as governor.; Therfore, the vehicle theives are out in force and don't worry about the consequences.
Diana in TX