A video of the incident showed people standing by, phones at the ready as the building near Taksim square -- a popular hub for tourists and shoppers -- began to rumble.
A white truck is seen frantically backing away, appearing to escape just in time as the building crumbles to the ground in one fell swoop, slamming into buildings across the road and scattering the curious bystanders.
The Dogan news agency said the building was empty, and that no-one was believed to be trapped by the debris, however disaster teams were despatched to the site as a precaution.
Residents of the city remain on edge after a suicide bomber killed four people and injured dozens in an attack on Istiklal avenue on March 19.
In 1999 a massive earthquake in the north-western Izmit region which left more than 17,000 dead exposed numerous weaknesses in building construction in the country, such as the use of low-quality cement and the lack of quality control.