The Royal Ontario Museum celebrated a key landmark yesterday. The ROM's CEO, William Thorsell, and Lead-Architect, Daniel Libeskind, were on hand as the final piece of the "Crystal's" structural steel was lifted into place. See News Release.

Here are some key facts about the project

Approximately 2,800 tonnes of steel, 3,000 steel pieces, 38 tonnes of bolts, and 9,000 cubic metres of concrete were used to complete the Crystal’s structure.

Construction workers and project engineers used laptops and 3-D illustrations to visualize how the steel shapes fit together. An 80-metre crane, erected at the centre of the site, lifted the beams, one by one, to a specific angle, with a three- or four -millimetre tolerance creating the complicated angle joints, sloped walls, and gallery ceilings, some that rise to almost 40 metres.

The steel beams, each unique and ranging from one metre to 25 metres in length, arrived in shipments of about 25 tonnes and were typically onsite for only a day prior to their installation.

With its highest peak at 36.5 metres, the northernmost tip of the Crystal will overhang the Bloor Street West sidewalk four stories above ground.