SPRINGFIELD, Mo. -

The Springfield Fire Department says the adults who were burned in a house fire on Thursday afternoon are Rachel Purcell, 28, and Derrick Pelliccio, 31.  Both are in the burn unit at Mercy Hospital.  Purcell was listed in serious condition and Pelliccio was in critical condition on Friday morning.

The adults were sleeping in a home in the 2000 block of West Mount Vernon Street when the fire started about 2 p.m.  Another adult and three children -- ages 5, 3 and 1 -- were also in the home.

Investigators said a child playing with a lighter started the fire in a bedroom where the two injured adults were sleeping.   The investigation found one of the children was left unattended with a long-stemmed butane lighter and ignited the bedding materials.  The fire is classified as accidental.

The third adult and the children got out without being burned.  The children were treated for smoke inhalation.  Fire marshals found no smoke alarm in the home, which suffered moderate damage that the fire department estimated would take $40,000 to repair.

Natalie Modglin, a witness who helped two of the children after the fire, saw Purcell crawl out of the home and scream for help.  She saw Pelliccio run out of the house with his clothes on fire. 

Modglin was in her car in the parking lot of a nearby nursing home when she felt a blast that she described as an explosion.   Other witnesses also described hearing an explosion, but fire investigators found no evidence of an explosion and said the sounds likely were the normal sounds of a big fire destroying a building.