US authorities have confirmed that the highly toxic pesticide methyl bromide caused a Delaware family to become seriously ill at a U.S. Virgin Islands resort , and that the chemical was used at the resort several times in the past year , officials said Tuesday . The US Environmental Protection Agency said it is contacting people including employees at Sirenusa resort in St. John to determine how many others might have been exposed to the pesticide . It was banned for indoor residential use in 1984 . 'Methyl bromide is a potent neurotoxin , so it really affects your central nervous system , ' EPA Regional Administrator Judith Enck said in a telephone interview . Steve Esmond and his wife , Dr Theresa Devine , and their two teenage sons fell seriously ill during their stay at the Sirenusa Condominium Resort on the island of St. John . The Esmond family had rented a second-floor condominium at Sirenusa , a resort of 22 villas , late last month . Steve Esmond and his wife , Dr Theresa Devine , and their two teenage sons fell seriously ill during their stay on the island of St. John . The family were airlifted to separate hospitals in Philadelphia suffering major respiratory trauma . Sean , 16 , and Ryan , 14 , were in critical condition . The family attorney James Maron confirmed the two parents are recovering but their two sons are in critical condition . James Maron , the family 's lawyer , said the boys were in 'rough shape ' . 'The family are all fighters , ' he told WPBF News . 'They 're fighting for everything right now . I understand it 's a long recovery . ' The US Justice Department has opened a criminal investigation . Sean , 16 , ( pictured ) and his 14-year-old brother Ryan remain in comas two weeks after being hospitalized . Enck said the pesticide was used March 28 on the condominium 's first floor , and agents are trying to determine how much was employed . She said the EPA found that methyl bromide was used at other Sirenusa units in the past year , but declined to say how many , citing the investigation . Sea Glass Vacations LLC , which rents units at Sirenusa , said in a statement it has terminated its contract with Terminix and the townhome under investigation is unoccupied . 'We are sending our thoughts and prayers to the family impacted by this tragic incident , ' the company said . 'We remain committed to full cooperation with all local and federal authorities . ' Terminix spokesman Pete Tosches said in a statement that the company is conducting its own investigation and is cooperating with authorities . 'We 're committed to performing all work we undertake in a way that is safe for our employees , customers and the public , ' he said . The family was staying at the $ 875-a-night Sirenusa Condominium Resort on St. John in the US Virgin Islands . Enck said the EPA is awaiting results of air and wipe samples taken from the condominium . Maron said Esmond , who is an administrator of the private Tatnall School in Wilmington , is conscious but unable to move . Devine , a dentist , was treated and released from the hospital and is currently in occupational therapy . The Tatnall school , where Sean was a star lacrosse player , posted on their Facebook page that they had the Middle School students write get wall cards for Esmond and his family . 'The entire Tatnall community continues to direct its supportive energy toward the Esmonds and asks that everyone keep the family in their thoughts and prayers during this difficult time . ' On Friday the US Environmental Protection agency said preliminary tests showed there was ' a presence of methyl bromide in the unit where the family was staying ' Tuition at the Tatnall school can range from $ 20,000 to $ 25,000 a year . Methyl Bromide , which is odorless , can be fatal or cause serious damage to the central nervous system and respiratory system , according to the EPA . It is acutely toxic , and only permitted to be used outdoors by certified professionals in the US . Sea Glass Vacations , which acts as a rental agent for several units at Sirenusa Condominium Resort , said the unit where the family was staying was not treated with a pesticide , but rather the unit immediately below their suite . Maron said when paramedics arrived at the villa Esmond was found unconscious .
Steve Esmond , his wife Theresa Divine and their two teenage sons fell seriously ill while staying at the Sirenusa Resort in St. John . Divine was released from hospital and is now in occupational therapy . The family has been left devastated by what happened to them during a holiday weekend that began with an overnight stay at the resort on Saturday before they were taken away for treatment of flu-like symptoms. On Friday the US Environmental Protection Agency said preliminary tests showed there was ' a presence of methyl bromide in the unit .