The Center for Building in North America coauthored a report with the Pew Charitable Trusts on single-stair apartment buildings, with a focus on cost savings and the safety track record in New York City and Seattle. On the cost side, we found that a second stairway for a mid-rise apartment buildings costs roughly $200,000 to construct. On the life safety side, we combined NFIRS data and reports of home fire fatalities from the U.S. Fire Administration, which we joined with property-level data in New York City, through which we found no evidence of any fire fatality attributable to the lack of a second exit in any of the more than 4,000 single-stair apartment buildings of at least four stories in the city. Similarly, we manually reviewed records of fatal fires in Seattle and found the same.