A medieval bridge is closed to traffic after a tractor driver caused "significant damage", the council says.
Police were called at 10:30 BST on Tuesday after the tractor got stuck on Bidford Bridge, in Bidford-on-Avon, Warwickshire, causing masonry to fall into the river.
The council said the parapet, wall and central pier of the "ancient monument" were damaged.
It said it did not have a reopening date. Bus services are being diverted.
Warwickshire Police said the driver of the crop tractor had "decided to go over the bridge" despite signs to prevent heavy vehicles from accessing it.
"It got stuck, damaged the wall and sections of the bridge fell off," the force said.
"Engineers are on the scene checking for structural damage."
Warwickshire County Council said the tractor driver had caused "significant damage to the ancient monument stone parapet, spandrel wall and central pier".
It said the bridge had now been reopened to pedestrians but needed "extensive repairs".
"A date to reopen the bridge to vehicular traffic is currently unknown," the council said.
The closure of the bridge has affected bus services into Worcestershire, with the 247 service from Redditch to Evesham diverting via Welford-on-Avon.