Investigations are continuing into what caused a massive fire that destroyed a leading computer science research unit at the University of Southampton.
The fire broke out in the early hours of the morning
Gas canisters exploded inside the Mountbatten building on Salisbury Road, Highfield, which was engulfed by a 100ft plume of smoke on Sunday morning.
No-one was hurt but the building, which housed valuable equipment for research, was gutted.
It has been estimated that the fire caused £50m worth of damage.
A spokesman said some of the world's most advanced research was carried out there and its loss was devastating.
The laboratory, part of the school of Electronics and Computer Science, was completely destroyed, and a nearby office building was damaged.
John Lauwerys, secretary and registrar at the university, said: "Some of the most advanced research work in the country, and indeed the world was carried out in this facility."
He said it would be some time before they could assess how much work has been lost.
"We probably will have to start from scratch, and it will take a couple of years to rebuild the facility," he added.
People living in the area were warned of potentially harmful fumes and told to stay inside and keep windows and doors shut. Flats above a nearby building were evacuated.
It took more than 100 firefighters nearly ten hours to bring the fire under control.
Resident Sarah May, who lives near the campus, said her family was woken up by a loud bang.
"There was a huge explosion, and literally seconds later there were police sirens everywhere.
"We looked outside and the sky was black. It seems to be lessening now, it's more of a grey colour, but the smoke is unbelievable."
Francis Chee, a postgraduate student at the university, was at the scene of the fire.
He said: "There are a lot of liquid nitrogen tanks outside the building and they use liquid nitrogen heavily there.
"I did hear several explosions sounding like gas canisters going off."
Police forensics officers and fire investigators have started to look for the cause of the fire which, at this stage, is not thought to be suspicious.