Authorities at Texas Tech University say an explosion inside a maintenance hole set off fires and power outages on the campus, leading school officials to issue evacuation orders for several buildings and cancel classes for the rest of the week.

Caitlynn Jeffries, a public information officer, for the Texas Tech Police Department, said the incident began around 7 p.m. with an explosion in a manhole near the engineering key in the central part of campus.

A day after the incident in which green flames could be seen coming out of manholes, 40% of the university in Lubbock remains without power.