Monrovia home goes up in flames after possible explosion

A Monrovia home was decimated by flames on Tuesday after what many neighbors in the area are calling an explosion. 
It was first reported at around 3:30 p.m. in the 300 block of E. Colorado Boulevard, according to the Monrovia Fire Department. 
Upon arrival, firefighters found large flames that were beginning to threaten another home nearby. 
By around 4:30 p.m. they had gained the upper hand on the fire, but not before it ravaged the home, leaving little behind, visible with SkyCal over the scene. 
Monrovia firefighters, assisted by Los Angeles Fire Department crews in the incident, say that one person is unaccounted for and a search is underway. They say that it may have been a tenant, but have not yet been able to confirm. 
It appeared that the home next door suffered some damage as the massive flames were able to extend to the structure. 
Neighbors say that the fire was preceded by a large explosion that sent shocks through the neighborhood.
“It was just a huge boom,” said Sherrie Vollaire, who lives near the scene. “I mean it shook the building.”
“All of the sudden the house just blew up,” Tim Price, another neighbor, said. “Full flames, just boom.”
The exact cause of the blaze remains under investigation, but Monrovia firefighters say that arson investigators have been called to the scene.