Baldev Singh, 40, wife Karamjit Kaur, 38, and seven-month-old daughter Khushpreet Kaur, who hail from Kaithal�district, were rushed to the civil hospital at Sonepat, where they were referred to the Post Graduate Institute of Medical Sciences (PGIMS), Rohtak.
The condition of Karamjit Kaur is stated to be critical. Doctors at the PGI told reporters that Karamjit Kaur had received more than 30% burns on her face and she might lose her sight.
According to details, Baldev Singh, who works as submersible pump mechanic at Sonepat, along with his family, was sleeping at his rented accommodation on the first floor. An unidentified person is believed to have climbed the first floor from the tree beside the house and thrown the chemical through the open window.
Around 3am, house owner Sant Ram heard the cries of the family and raised the alarm. Meanwhile, the attacker fled from the spot.
A police patrol nearby rushed the victims to hospital. Baldev Singh said as the family was sleeping, they could not know as to who attacked them.
The police said a case had been registered against unidentified persons under Sections 323 (voluntarily causing hurt) and 326 (voluntarily causing grievous hurt) of the IPC.
No arrests have been made so far.