GAITHERSBURG, Md. (WUSA9) -- A small explosion Sunday at the NIST's Gaithersburg campus is being investigated as a possible chemical explosion due to drug manufacturing, Montgomery County police say.

According to police, the explosion happened at around 7:30 p.m. Sunday at the NIST's Bureau Drive campus.

A spokesperson for MCPD said the explosion was caused by a lab process that happens on a routine basis. An error occurred, which caused a small explosion that triggered heat sensors in the building.

GAITHERSBURG, Md. (WUSA9) -- Police are investigating a robbery that happened at the Express Check Cashing Office in Gaithersburg on July 6.

The robbery happened at the Express Check Cashing Office located at 8359 Snouffer School Road in Gaithersburg around 9 a.m., according to authorities.

The investigation shows that the suspect entered the building when it was being opened for business. The suspect was armed and forced the employee to hand over the money. The suspect then told the employee to stay in a rear room and he fled with an undisclosed amount of money.

GAITHERSBURG, Md. (WUSA9) -- It has been six months since a deadly plane crash right in the middle of a Gaithersburg neighborhood, and some homeowners impacted by the crash remain out of their homes.

The worst part, they say, is they're not sure why.

"The house is kind of the same way it was on December 8 when the plane hit," a woman whose home was damaged in the crash said.

Six people, including a mother and her two children, were killed and three homes were damaged or destroyed in the crash.

"I've been told this is part of the data recorder and I guess these are other pieces that never got picked up," the woman, who spoke on the condition of anonymity said.

"Nobody has come out to clean anything up yet. They've done some testing and found various levels of petroleum, I guess, but haven't really reported back to us about where to go from there."