"There's six floors in the building; each floor has one apartment," she said. "Last night it smelled like gas, but then the smell vanished and we all went to sleep."
Salas' family continued to hold out hope Thursday that he'd be found alive.
His father-in-law, Jorge Ortega, told The Associated Press that the 21-year-old was last seen Wednesday morning when he returned from his night job at a Bronx restaurant.
Ortega said his distraught daughter, who is six months pregnant and whom he identified as Jennifer Mendoza, went to the hospital Wednesday but was resting at his home on Thursday.
Ortega said Jordy Salas' father was up all night waiting for any news.
Edward Foppiano, a Con Ed senior vice president, said there was only one gas odor complaint on record with the utility from either address, and it was last May, at the building next door to Borrero's. It was a small leak in customer piping and was fixed, he said.
The block was last checked on Feb. 28 as part of a regular leak survey, and no problems were detected, Foppiano said.
One of the side-by-side buildings had a piano store on the first floor, the other a storefront church.
City records show that the building Borrero lived in was owned by Kaoru Muramatsu, proprietor of the piano business. A phone number listed for Muramatsu rang unanswered.
Records at the Department of Housing Preservation and Development indicate the agency responded to complaints from a tenant and cited Muramatsu in January for a broken outlet, broken plaster, bars over a fire escape, a missing window guard and missing carbon monoxide and smoke detectors.
City building records don't show any work in progress at either address, but the building owned by the Spanish Christian Church had obtained permits and installed 120 feet of gas pipe last June.