Two workers are still trapped after a trench collapsed at a road construction site in Ajax and two others have been taken to hospital, Durham Regional Police say.
Police said the industrial accident happened on Rossland Road West near Westney Road North on Monday. Officers were called to the scene at about 12 p.m.
An excavator worked for hours during the day and into the night to try to free the two workers. Their family members were believed to be at the scene, watching the rescue operation.
Police have confirmed that emergency crews were there on Monday night.
Of the two who were injured, one was taken to a local hospital, while another was airlifted to Sunnybrook Health Sciences Centre, police said.
Ontario's Ministry of Labour said in an email on Monday that it is not known how badly injured the workers are. It said a ministry inspector has been assigned to the case and was at the scene on Monday.
"It has been reported that four workers were buried in a trench, and two workers are still believed to be buried at this time," Anu Dar, ministry spokesperson, said in the email.
Ajax Fire and Emergency Services was in control of the scene.
Police have closed Rossland Road West between Westney Road North and Ravenscroft Road as the investigation continues.