WILSONVILLE, Ore. -- Parents at a Wilsonville elementary school were asking for answers Thursday after they said their children were exposed to porn in the classroom.

Most Google search results for "puffer fish anatomy" turn up information and pictures of the peculiar fish. But parents said a third-grader researching a school project was directed to an adult site, despite the school's firewall protection.

Boones Ferry Primary School parents said they're angry they had to find out about it from other parents and not the school. Tom Sherry said his son was one of several third- and fourth-graders who were exposed to the pornographic Web site.

"It slips through and I can understand that, but they need to notify the parents," Sherry said.

Jodi Santo, another Wilsonville parent, said students shouldn't be seeing inappropriate content on school computers. "Who knows how many other students saw it too?" she said.

The site is now on the school's list of blocked content. Superintendent Roger Woehl said the district has firewalls in place, but he said inappropriate sites slip through once or twice a year.

A student at the school said they're no longer allowed to use Google.

"We can't do Google anymore; I think cause of that," said Lucas Whitesell, a Wilsonville fifth-grader.

Sherry said the incident forced him and his son to have a talk he didn't want to have.

"It wasn't very comfortable having to discuss that at that age, especially with the type of pictures that he saw," Sherry said.

Sherry said he wants to see the school come up with a plan to let parents know right away if students see pornographic content.

Since the incident, teachers at the school have talked to students about Internet safety and responsibility.