After a crane overturned, rescue workers were called to the port of Middlesbrough.
The machine collapsed at logistics company AV Dawson on Wednesday, damaging two other cranes and spilling fuel.
The company announced that there were “no serious injuries” after the collapse.
The Cleveland Fire Brigade and AV Dawson response teams managed to contain the fuel leaks.
The crane is operated by the Sarens engineering office.
A spokesman for AV Dawson said: “There was an incident on our quay at 4:19 pm on Wednesday where a Sarens crane was working on behalf of a tenant in Middlesbrough harbor.
“We are grateful to report that there were no serious injuries, but we can confirm that two Sarens cranes and a mobile harbor crane were damaged during the incident.
“During the emergency call, all leaks from the cranes were contained and repaired by our emergency teams and the fire brigade.
“We take health and safety very seriously and conduct strict security checks on all third parties working on our site. We will now work closely with Sarens to support them with their internal and external investigations.”
A Cleveland Police Department spokeswoman said officers were present but “there was no need for police to remain on the scene as there were no injuries and no major problems.”