Morgan City Assistant Police Chief Glenn Blanco said there is an investigation but there are no suspects.
Meanwhile, negotiations are continuing into who will pay for repairs to the sagging building.
Carrie Stansbury, executive director of the Cajun Coast Visitors and Convention Bureau, said someone tried to get inside the building through the back, but was unable to obtain access.
The gates — normally locked since the nearly $4 million building began sinking into the swamp June 14 — were open because the City of Morgan City required access to its substation next door for work.
An employee of Aegis Construction, who checks the tourist commission building daily, noticed the damage and notified authorities, Stansbury said.
Mediation to try to determine who will pay for the damages to the failed building continues even though no physical meetings have been held since early September.
On Sept. 10, less than 90 days after the foundation failure at the welcome center, the principal parties involved in the design and construction met for mediation. Since that date, the parties have continued discussions both through the mediator and directly with each other.
In general terms, they need to determine the method of repair; the sources of payment; warranty issues; the performance bond, surety and insurance issues; and public works issues involved in the entire process, Cajun Coast attorney Gary McGoffin said.
No details of the mediation talks are available as they are confidential and some proprietary repair processes are included.