It should be business as usual Tuesday around Downtown Austin, but there's still no word on what caused the deaths of more than 60 birds.

Preliminary tests showed no dangerous chemicals in the area, and the bird flu has been ruled out.

While officials search for answers, they say they're confident that there's no public health threat.

"Yeah, it sounds most like a poisoning, if I had to guess," said Jacob Mireles, D.V.M., with the Brykerwood Veterinary Clinic, "and I'm pretty sure that's what it's going to come out as."

The carcasses of the more than 60 grackles, sparrows and pigeons have been sent to Texas A&M, where tests will be performed on Tuesday.

Also, some are asking if it was really necessary to shut down the heart of the city because of these dead birds. Those who made the call at City Hall say there really is no question.

"We're finding out now that we don't feel that there was anything there. There was no risk to public health, but you don't know that until you work your way through the investigation," Asst. City Manager Michael McDonald said.

These birds can be a nuisance to a lot of business owners and people downtown. If someone poisoned the birds, could that person be held liable for the costs associated with the emergency response?

The city's legal team told KXAN Monday they wouldn't answer that question until they know for sure what killed the birds.