The bridge in Stone has had to be closed after it was set on fire.
Officers were called at 3.10pm on Sunday to a bridge close to Morrisons on Mill Street following reports of public order offences.
Police attended found that a fire, believed to have been set deliberately in the previous 24 hours, had caused significant damage to the bridge, putting it out of use to the public.
Staffordshire Fire and Rescue Service informed the local authority who are due to make repairs to the bridge.
Police are currently reviewing CCTV footage of the area at the time and ask anyone who saw what happened to get in touch.
Contact Staffordshire Police on Facebook, Twitter, or call 101, quoting incident number 479 of 30 May.
Alternatively, contact Crimestoppers anonymously on 0800 555 111.