At least one person has been killed and several more were injured in a gas blast which caused a building to collapse in Carolina.
An evacuation of the site in Durham was under way when it exploded injuring 17 people, six critically, on Wednesday.
Firefighters were working to clear the surrounding area as they responded to a gas leak shortly after 10am (local time).
The deadly blast destroyed the entire building which houses a building technology company.
A firefighter was among those injured.
Emergency crews were working to rescue further victims who may be left trapped in the rubble.
Officials said the cause of the explosion was under investigation.
A contractor boring under a pavement had hit a gas line, causing the leak, Durham Police Department spokesman Wil Glenn said.
The explosion came about 15 minutes after fire crews were alert to the smell of gas nearby, according to local reports.
Agencies contributed to this report
