Firefighters in Lawrence, Massachusetts and surrounding areas responded to at least 70 natural gas fires or explosions Thursday. Electric power was cut to the area to prevent sparks that could set off more blazes and a general evacuation was announced. This is the most recent map of the fires published by state police:

Earlier, police indicated multiple neighborhoods were being evacuated:

As I was writing this, the Mayor of Lawrence requested that all residents leave the area:

Obviously, with it getting later on the East Coast, there is a danger that people could go to sleep in houses that fill with gas overnight. Here’s what the evacuation order sounds like on the street:

There are multiple videos showing some of the homes that have caught fire in the area:

It’s unclear how many people have been injured in the fires an explosions so far. It may be a few hours until authorities have a tally. As for what caused all of this, the consensus seems to be that it’s the result of a gas line pressure problem. The Boston Globe notes that some work on gas lines in the area had been announced earlier today:

The Columbia Gas website said in a posting dated Thursday, “We’ll be upgrading natural gas lines in neighborhoods across the state.” The site said that four projects were underway in Lawrence, four in Andover, and three in North Andover…

Overpressurization of gas lines has caused problems before. In November 2005, overpressurization of gas lines caused widespread gas leaks in Lexington, triggering the fiery destruction of one house, near explosions at seven others, and leaving hundreds without heat amid cold weather.

For now, the area is just trying to cope with an unplanned mass evacuation of tens of thousands of people on top of putting out dozens of fires.