'I Saw Families Screaming': Witnesses Recount London High-Rise Inferno as Casualties Mount

Those on the ground beneath London's Grenfell Tower saw a horror unfold as the 27-story residential building erupted in flames Wednesday.

A horror unfolded in London Wednesday as a blaze ripped through a high-rise quicker than some could escape and killing no fewer than 12 people.

Witnesses say they watched the fire engulf the lower floors of the 27-floor Grenfell Tower first before swiftly climbing its sides, as some trapped residents gazed helplessly out their windows at frozen onlookers below.

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"It was horrific. I saw families screaming, people looking like they wanted to jump out," local resident Yousef Serroukh, 18, told reporters.

Serroukh's experience mirrored that of many witnesses to the fire in North Kensington, where firefighters fought tirelessly to beat back the flames that broke out sometime around 1 a.m.

"We saw people looking out the window screaming, 'Help! Help!' Now all those windows, those people are literally gone," one witness recalled.

While fire personnel arrived within minutes of the first reports of the blaze, London's fire commissioner says they weren't able to save some of those who couldn't get out.

"There have been a number of fatalities. I cannot confirm the number at this time," Dany Cotton said as early reports indicated six were killed before the count started to tick up.

Dozens of injured residents were rushed to London hospitals as officials warned the process of recovering the dead could be a long one.

Firefighters continued to make rescues many hours after the blaze, which was put out around dawn. Even then, a billowing cloud of smoke could be seen for miles.

Officials did not immediately know what caused the blaze. 

Grenfell Tower recently underwent a multi-million dollar renovation, with many of its 120 apartments having been outfitted with new windows.

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While many witnesses seemed sure the fire seemed to grow along the outside of the tower, it was not clear whether the building's facelift was related.

Emergency shelters have been set up in the area for those with nowhere to go.

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