Residents have been evacuated after part of the back of a house collapsed.
It left a pile of rubble and some of the remaining building was exposed in Mount Pleasant in Redditch, Worcestershire, at about 00:05 BST.
No-one was injured and a search and rescue dog was used to check whether anyone was trapped underneath.
Neighbouring properties were evacuated while the house was made safe. The cause of the damage is not yet known and engineers will examine the site.
Some construction work appears to have been taking place at the back of the property.
Robert Allen, group commander for Hereford & Worcester Fire and Rescue Service, said at least two families, and a business, have been affected by the evacuation and will be supported by the British Red Cross.
He said the homes are privately rented, and new accommodation will be arranged.
Specialist search and rescue teams were brought in to help, including lights and thermal imaging cameras to check the area, after a "substantial" part of the building collapsed.
Firefighters have been on site for more than 12 hours but have handed the incident over to Redditch Borough Council, which has been approached for comment.
A structural engineer and gas workers ensured the scene was safe.
Assisting @HWFireRedditch in the early hours assessing the structure of a partial collapse and ensuring no one was involved using @HWFireDroitwich search dog, USAR team and @WalesFireDogs all part of our @HWFire USAR teams skills in @USAR_Capability #notjustfires pic.twitter.com/gb4Ruy3X7M— Phill Sanders (@HWFirePSanders) July 15, 2018
Mr Allen said: "We are waiting for structural engineer feedback on what happens from here.
"Naturally we are concerned about how vibrations from the road will affect the structure of the building.
"We have semi-permanent barriers cordoning off Mount Pleasant and Beaufort Street and until we have the assessment of the structural engineer, we don't know how long they will stay in place."
He said the council would be providing further advice to residents.
Police cordoned off the scene, with road closures in place from Ipsley Street to the junction with Salop Road, including Beaufort Street.
It is not yet known how long the roads will be closed for.
Multi agency approach to the partial building collapse at #mountpleasant #Redditch with @WorcsTravel & @RedditchMatters @WMerciaPolice securing the area with fencing. @HWFireDroitwich now assisting pic.twitter.com/7sbaNTVFGr— Robert Allen (@HWfireRAllen) July 15, 2018