Shocked residents said they heard a 'loud bang' from the city dock area where a man died this morning.
Emergency services were called to Prospect Road at Sunderland docks shortly before 10am today.
It is confirmed that a man has died following what was a suspected accident.
Geoff Moon, 55, landlord of the nearby Welcome Tavern for 27 years, told how a number of emergency services vehicles were quickly on the scene.
He said: "We just heard a loud bang.
"The local authority was digging up the road outside and those lads thought it was thunder because we've had thunder and lightning in the area, but to me it was much sharper, like an explosion.
"Very shortly after that we heard the emergency services and we knew then it was something serious because the response was so quick.
"We saw an ambulance go by and a police car.
"The noise was like a boom, but not like thunder which rumbles on."
Local resident Eileen Lovert, 73, said: "I heard this almighty bang, I got out of bed after that and I looked out and all I could hear was sirens going.
"After that, the thunder started, but what I heard was definitely more of a bang. It was very different to the thunder.
"I felt the house move a little bit. It did sound like an explosion. I saw an ambulance going down to the docks."
Doreen Rowntree, 75, said: "It was a heck of a bang.
"It wasn't like thunder and lightning, it was more like a crack. It was almost like a bomb was going off."
The Port was closed off to traffic while emergency services were on the scene, resulting in several trucks parked up outside waiting to get on site.