The Ulhas River is a river in Maharashtra, India. It is in the Thane, Raigad, and Pune districts of that state. It flows north and west from it source to where it splits into Vasai Creek and Thane Creek, near Thane. From Wikipedia
The students, aged 15-16, drowned while washing off Holi colors in a dangerous stretch of the river in Badlapur, Thane district.