COLUMBUS, Ohio (WCMH) — The Central Ohio Transit Authority’s buses are running, but its website is not after its information technology network experienced a cyber security breach.

COTA announced Wednesday that it learned an “outside organization” accessed its IT network on Monday. In response, the transit authority shut down networks for all of its IT systems while cyber security experts investigate the incident.

“To protect COTA’s employees, customers, data, and systems, we took the proactive approach of taking all our IT systems offline,” a press release read.

When NBC4 tried to visit COTA’s website on Wednesday, it returned a dead page. The transit authority also said its emails and phone are offline, although its services, including its bus routes, COTA Mainstream, COTA Mainstream On-Demand and COTA Plus will operate as normal. Customers looking to book trips with COTA Mainstream can call 614-344-4488 in the interim.