A private co-ed school in Tarrytown went up in flames Saturday and officials believe it was caused by a powerful lightning strike.

The Hackley School was founded in 1899. The intense fire destroyed its library and surrounding buildings. Fire officials say the flames could have started as early as 3 a.m. They say that is when they received calls from motorists on Route 287 who could see smoke billowing from the heavily wooded area.

More than 300 firefighters from Ardsley to Nyack were on the scene trying to contain the stubborn flames and heavy smoke hours after the fire started. Fire officials say the biggest challenge was getting water on the fire. Crews on the scene say they didn't have enough to douse the flames and had to call in more tankers to get the job done.

The historic Hackley School is considered one of the most prestigious private co-ed schools in the region, with most graduates going onto Ivy League colleges. The school has day students in kindergarten through twelfth grade and boarding students in ninth through twelfth grades. School is set to begin in less than a month, and officials don?t know if the library will be operational by then.