crash, crass

Crash or crash means to come into contact violently or destructively --
You're driving too fast; you'll crash into the wall!
Don't crash into the mailbox on your way out.

Crash or crash also means a collision, a violent or destructive  meeting --
The police were already at the crash site.
He swerved just in time to avoid a crash.

Crash or crash also means to show up at a party or event uninvited --
Should we crash the party? We know some of the kids.

Crass or crass means crude, unrefined, or insensitive --
He thinks any mention of money is crass.
She can't resist making some crass remark about what the other women are wearing.

Now that you know that, you can say --
"We thought it was crass, but he just had to hear every detail of the crash."

crash, clash

Crash or crash means a physical impact or collision--
Broken glass from the crash was all over the road.
He remembers every car crash from the movies and TV.

Clash  means a loud or disagreeable noise--
The clash of the cymbals made him jump.
We heard a clash that sounded like someone knocked over some metal pots and pans.

Clash or clash most commonly means a conflict of personalities or opinions--
We get tired of the way their personalities clash whenever they meet.
The clash of their political opinions nearly spoiled the dinner.

Clash also describes colors or patterns that do not agree, or that don't match--
Does this tie clash with my suit?
Most people agree that blue and orange clash.

Now that you know that, you can say--
"We could hear the clash of metal hitting metal a block away from the crash."