Emergency engineers have been called to deal with a 6ft-deep void that appeared to open suddenly on a residential street near Northampton town centre.
The sinkhole in Overstone Road, right outside the Lamplighter pub, was first spotted by a member of the public at around 7pm on Friday night (June 16).
People living in the area had noticed a slight dip in the road in the days beforehand, but many considered it to be just a pothole.
On Friday, it is understood to have suddenly caved in, leaving a 4ft-wide hole that has become a target for litterbugs. Police cordoned it off shortly afterwards and an 80-metre stretch of the road remains closed today (Monday, June 19).
The cause of the collapse is not yet known, though a spokeswoman for Anglian Water confirmed emergency engineers were being dispatched to the scene today to investigate.
Rufus Fox, 22, a barman at the Lamplighter, was working when the hole appeared.
"There was a guy walking past who saw and came rushing in here and said you might need to 'let someone know about this'.
"The size it is now is about the size it was when I first saw it.
"One of our locals said he saw it a few days ago when it was tiny.
"It just got a lot bigger."
A spokesman for Northamptonshire County Council said: “We have been made aware of the carriageway defect in Overstone Road, Northampton, and will send out a maintenance crew to investigate.
“It is anticipated that the work will be completed in the next few days.”