seriously ill with covid. david? >> yeah, those were very alarming numbers we learned today. eva, thank you. next tonight here, to the explosion and partial collapse in dallas. firefighters injured, three in critical condition tonight. the firefighters were investigating a possible gas leak, but then caught there when the blast occurred. part of the building turned to rubble. firefighters on the pile. abc's marcus moore on the scene in dallas tonight. >> reporter: three firefighters in a fight for their lives tonight and families in this south dallas neighborhood are homeless. after a powerful explosion leveled part of this apartment building just before 10:30 this morning. >> truck 25. truck 25. we need rescues! truck 25. >> looks like we have a total collapse of the front half of the apartment. >> all of a sudden, i just heard a big boom and the glass -- the glass shards just started flying. looks pretty significant. and officially, we cannot imagine that there would be anything to salvage. >> reporter: the blast injured