A deliberate explosion at Harvard Medical School in Boston appears to have been two young adults playing a prank – a relief to the school that’s been on edge since the blast early Saturday morning.

Two suspects – 18-year-old Logan David Patterson, and 20-year-old Dominick Frank Cardoza – were arrested by the FBI’s Boston Joint Terrorism Task Force after the explosion, which left a fourth-floor hall in the prestigious school’s Goldenson Building damaged.

Both men were charged with one count conspiracy to commit damage via an explosive, The Boston Globe reported. 

The Massachusetts locals were found to have been playing around with Roman candle fireworks across the prestigious campus just minutes before the blast, with security footage capturing them scaling the building and entering through the roof at around 2:30 a.m.

Then around 2:45 a.m., smoke detectors in the Goldenson Building – which holds neurobiology research labs – started going off, officials told reporters at a Tuesday news conference announcing the arrests.

Patterson and Cardoza were caught on camera fleeing from the scene with their faces covered – with Cardoza even stripping off his pants and tossing them in a dumpster after investigators said they apparently realized they’d been filmed.

Both were arrested after members of the public identified them from released security footage and reported them to police.

They allegedly lit one of their Roman candles in a locker, and the explosion caused a fire.

Nobody was hurt in the incident, and the blast site has since been cleared and re-opened.

Cardoza and Patterson even later boasted about their alleged behavior to friends, according to police.

Federal investigators said they worked around the clock over the weekend to apprehend Patterson and Cardoza, adding that the investigation was ongoing.