The iconic diamondback-pattern pavers of 16th Street were more than just stone cold on Thursday morning – they were also slick with ice.

In typical Colorado fashion, the shaded parts were dicier, while sections exposed to sunlight quickly dried following Denver’s first major snowstorm of the season and the first since the downtown destination fully reopened after its major reconstruction.

Downtown’s main street — formally known as 16th Street Mall — used to be made up of granite pavers once infamous for a slippery texture in rain and snow.

Amid its reconstruction, the city installed more than 950,000 new pavers designed to increase the friction between the stone and the soles of pedestrian shoes. 

It doesn’t mean they’re invincible, though.

Overnight, temperatures recorded at the Denver International Airport dropped from 27 degrees to less than 13 degrees Fahrenheit, according to the National Weather Service.

City Park, east of downtown, saw about 5.3 inches of snow over 36 hours.

Many of downtown’s streets were slippery with slushy snow that refroze overnight. One woman slipped and fell at the intersection of 18th and Welton on Thursday morning, causing her to drop all her belongings.

But 16th Street is made of entirely different materials than the rest of downtown’s roads and requires special care to maintain. The snowstorm on Wednesday was one of the first major tests for the street since it fully reopened.

For one morning commuter, Adriana Martinez, it was a bit of a struggle to walk on 16th Street in the morning, especially in her heels. 

“Aside from that, it’s been a little breeze because I got a lift,” Martinez said. “If I see snow, then I step on it. It makes it easier to walk on the ice.”

One of the top complaints about the old 16th Street Mall’s pavers — inspired by diamondbacks in rattlesnake and Navajo rug patterns — was its slipperiness, said Britt Diehl, a spokesperson for the Downtown Denver Partnership. Improving the material became one of the top priorities for new pavers.

The new material is still granite, but the city chose coarser and smaller pavers to maximize friction as part of the construction project that was completed in October and cost more than $172 million. 

Protecting the mile-long stretch of pavers requires different snow removal methods to keep it preserved for as long as possible, while keeping it safe for commuters in tougher weather climates.

“Because these pavers are so precious, we can’t use traditional snow melt that you would be able to use on roads and sidewalks,” Diehl said.

The Downtown Denver Business Improvement District is allowed to use light machinery in the FreeRide transit lanes, she said, but most of the snow and ice removal is done by shoveling the sidewalks by hand. 

The organization is still experimenting with what works best for 16th Street in different weather conditions, Diehl said. They began testing different processes when parts of the mall reopened last year, when they learned light snow removal machinery can operate in the transit lanes.

“Today’s snow event is a little bit different than a typical snow because we saw that really dramatic temperature shift,” she said. “And, so, it’s just a lot icier than what we normally see.”

Due to the conditions, she said, they even brought out sand on Thursday to test it out.

If conditions continue to be slippery, Diehl added, they will consider using ice melt as a last resort but will avoid it as long as they can to not damage the pavers.

“We really are working hard to make sure that we find the exact right approach to how we keep this space clean,” she said.

Reporter Emily Bejarano contributed to this report.